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Trunx Rooftop Cargo Box - 18 cu ft - Black

Trunx Rooftop Cargo Box - 18 cu ft - Black

Item # TRX34FR
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Our Price: $636.05
Roof Box
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Shipping Weight: 37 lbs
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Roof Box TRX34FR - Passenger Side Access - Trunx
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56-1/2 x 38-3/4 x 19. Roof box mounts to your crossbars with U-bolts and hand knobs. Locking lid opens from the rear. Carries camping gear, sports equipment, and other cargo on larger CUVs and full-size SUVs. Durable, HDPE thermoplastic construction. Lowest Prices for the best roof box from Trunx. Trunx Rooftop Cargo Box - 18 cu ft - Black part number TRX34FR can be ordered online at etrailer.com or call 800-298-1624 for expert service.
  • All Info
  • Reviews (7)
  • Q & A (18)
  • Photos
  • Why etrailer?

Trunx Roof Box - TRX34FR

  • Aero Bars
  • Elliptical Bars
  • Factory Bars
  • Round Bars
  • Square Bars
  • Large Capacity
  • Trunx
  • Short Length
  • Black
  • High Profile
  • Passenger Side Access

56-1/2 x 38-3/4 x 19. Roof box mounts to your crossbars with U-bolts and hand knobs. Locking lid opens from the rear. Carries camping gear, sports equipment, and other cargo on larger CUVs and full-size SUVs. Durable, HDPE thermoplastic construction.


  • Cargo box mounts on your vehicle's roof rack to provide enclosed storage for your gear
    • Perfect for carrying sports equipment, camping gear, or luggage for up to 4 people
    • Great for most full-size SUVs and larger CUVs
  • Rear-opening lid lets you load and unload gear from the passenger's side of your vehicle
    • 2 Metal struts hold the lid open
  • Built-in lock secures gear in box and secures box to crossbars
  • Latches on front, rear, and driver's side of box ensure lid is completely closed
    • Can be locked with padlocks (not included) for added security
  • Tool-free installation with included U-bolts, hand knobs, and plates
  • Aerodynamic shape helps minimize wind noise and drag
  • Compact storage - removable lid nests in base when not in use
  • Durable, HDPE thermoplastic construction
  • Matte black finish
  • Made in the USA


  • Application: most round, square, aero, elliptical, and factory crossbars
    • Maximum crossbar dimensions: 3-3/4" wide x 1-3/16" tall
  • Crossbar spread: 22"
    • Can be expanded to a maximum of 31" (requires drilling)
  • Carrying capacity: 18 cu ft
  • Weight capacity: 100 lbs
  • External dimensions: 56-1/2" long x 38-3/4" wide x 19" tall
  • Internal dimensions: 56-1/3" long x 38-1/3" wide x 18-1/3" tall
  • Box weight: 29 lbs
  • Limited lifetime warranty

Car Top Cargo logos

Mounting Diagram

TRX-18L Trunx Roof Cargo Carrier - Large - 18 cu ft - Black

Replaces Car Top Cargo CTC-18S

Customer Reviews

Trunx Rooftop Cargo Box - 18 cu ft - Black - TRX34FR

Average Customer Rating:  3.0 out of 5 stars   (7 Customer Reviews)

56-1/2 x 38-3/4 x 19. Roof box mounts to your crossbars with U-bolts and hand knobs. Locking lid opens from the rear. Carries camping gear, sports equipment, and other cargo on larger CUVs and full-size SUVs. Durable, HDPE thermoplastic construction.


Put it together in just a few minutes. Very easy. Haven't actually mounted it to the car yet. In my case, I think side opening would be preferred as the Traverse is very tall and will require a small step ladder to reach the lock.


Save your money and do not buy this product, it's poorly manufactured to say the least. 1), the plastic gauge is way to thin making the final product to flimsy. 2) while the order information asked me for make, model and year of vehicle it did not match factory rail specifications. The factory roof rack system for Honda CRV is not adjustable and the 22 inch spread identified for product does not work for Honda installed roof rack systems. 3) lastly, the hinge design on this unit is poorly designed and will not align without modifications to bend the tabs so that they properly align with the slots. Once again, do not waste your money on this product.

This rooftop cargo box can accomodate up to a 30 inch spread on some crossbars, but it would involve drilling to the custom measurements of your CR-V crossbar spread.
-- Etrailer Expert Rachael H - 09/17/2019


I have a 1 star because I am very disappointed in the quality . The plastic Cover is badly warped out of the box making it very difficult to close. For the price of this product I am dissatisfied with the quality.


The roof top box is definitely big enough for my all my family's gear, planning a road trip out West that includes some camping along the way. The plastic was a bit flimsier than I had expected and I was NOT impressed with the PLASTIC clamps around the side. I'm not too worried of the lid flying off if a clamp or two breaks - the front of the box locks and there is a pin in the rear hinge - however, I'm packing extra rope just in case. It also appears that the rivets holding the rails and lock to the container are also made of plastic. I do a lot of camping, I'll likely update my review after putting it through a few runs.


I am not completely satisfied with this product, although it holds things ok. Made of plastic that is very flimsy/flexible. Would be better if it was rigid plastic. Also find the support holders are a bit difficult to put onto the little pegs (can't really see them do to being inside). Purchased for our make and model and still had some difficulty installing. Was not pleasant and I usually enjoy doing projects.


by: 07/15/2021


Ask the Experts about this Trunx Roof Box

  • Roof Rack for 2018 Buick Encore to Use Trunx Rooftop Cargo Box
    A roof rack does need to be purchased separately for your 2018 Buick Encore to install the Trunx Rooftop Cargo Box # TRX34FR. The roof rack used in the video is a Rhino-Rack and is truly the best option for a roof rack for your '18 Encore because it is the best value. The Rhino-Rack is the most budget-friendly roof rack that fits your Encore but is still a very high quality so I strongly recommend going this route. The rack will mount to the flush rails on your Buick and is made up of...
    view full answer...
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  • What is the Largest Cargo Box that Will Fit a 2020 2020 Toyota 4Runner TRD Pro?
    The largest roof cargo carrier we have that will fit the 46 inches from the front crossbar to the line where the roof and the hatch meet (in order to open the rear hatch) is the Trunx Rooftop Cargo Box - 18 cu ft - Black # TRX34FR with interior dimensions of 56-1/3 inches long x 38-1/3 inches wide x 18-1/3 inches tall. The Trunx Rooftop Cargo Box will fit on your factory crossbars with a maximum width of 3-3/4 inches and a maximum height of 1-3/16 inches. The Trunx Rooftop Cargo Box...
    view full answer...
  • Will the Trunx Rooftop Cargo Box Fit for a 2017 Audi Q5 with 28 Inch Crossbar Spread
    The Trunx Rooftop Cargo Box - 18 cu ft - Black # TRX34FR comes setup for a 22" crossbar spread but can be expanded out to 31", so it will work for your 28" spread. You will need to drill new holes and the method that you've mentioned will work well to fit this to the crossbars on your 2017 Audi Q5.
    view full answer...
  • What Options Do I Have for a Mounting a Cargo Box and a Basket at the Same Time on My 2020 4Runner?
    I have a solution for you. Unfortunately, we do not currently carry crossbars that are long enough that are recommended for your 2020 Toyota 4Runner that will let you attach the Trunx Rooftop Cargo Box - 18 cu ft - Black # TRX34FR along with your 33-1/2 inch long x 49 inch wide cargo basket. Also, we currently do not carry any hard cargo boxes that will allow you to safely attach it to your basket. With that being said, if you remove your cargo basket, the Trunx cargo box will fit your...
    view full answer...
  • Crossbar Spread Required for Trunx Rooftop Cargo Box
    I'm certainly sorry to hear about the cargo bag issue you had going through a snow storm. Cargo bags are really handy and easy to manage but weather can be an issue so you are smart to go with a cargo box. The Trunx Rooftop Cargo Box # TRX34FR you referenced uses U-bolts that will work on crossbar spreads from 22 inches to 31 inches and the spread of the SportRack Roof Rack # SR1010 on your Ford Fusion is going to be in that range so it is definitely going to work. The cargo box will...
    view full answer...
  • Roof Cargo Box that Can Fit 2021 Toyota Sienna with OEM Crossbars
    The Trunx roof top cargo box part # TRX34FR can fit the crossbars of your 2021 Toyota Sienna but you would need to drill new holes in the box unless your crossbars can be placed right at 22 inches. Basically any roof cargo box will fit your vehicle but if you wanted something a little nicer yet in same price range the Malone Profile18s part # MPG910 would be a really great option. It has a sleaker design, opens from the side, and has easier to use mounting hardware as well.
    view full answer...
  • Will the SportRack SkyLine Cargo Box Fit on Factory Crossbars of a 2018 Kia Sorento
    Yes. The Trunx Rooftop Cargo Box - 18 cu ft - Black # TRX34FR is designed to fit on most aftermarket and factory roof rack crossbars, so as long as your 2018 Kia Sorento's factory bars aren't wider than 3-3/4" this box will fit without any issues. Most crossbars aren't that wide and I have yet to encounter a factory crossbar that this box hasn't fit on, so the Trunx cargo box will do a great job.
    view full answer...
  • Replacement Mounting Hardware for Sears Sport SP-20SV Rooftop Cargo Box
    We have replacement mounting hardware for a Sears Sport SP-20SV cargo box, but the Replacement Mounting Hardware for Car Top Cargo Roof Cargo Box # CTC-18PARTS is only a fit for the Trunx Rooftop Cargo Box # TRX34FR. The correct mounting hardware for the SP-20SV is the Replacement Hardware Kit for Searsbox Cargo Box # TH05603. We don't carry that cargo box, and we would be unable to confirm any specific fits, but I believe it is a universal fit so there's no reason to think it won't...
    view full answer...
  • What Roof Rack System and Rooftop Cargo Box Will Work on Factory Flush Rails on a 2016 Lexus GX 460?
    I have a solution for you. Yes, the parts that you listed are correct for a complete roof rack system on your 2016 Lexus GX 460. However, the crossbar dimensions of the Inno Aero Crossbars # INXB123-130 are not compatible with the Malone Profile18S Rooftop Cargo Box - 18 Cubic ft - Gray # MPG910. Since the Profile18S requires a crossbar width between 1-3 inches, it is not compatible with the 3-1/8 inch wide Inno Aero Crossbars. With that being said, I recommend the Trunx Rooftop Cargo...
    view full answer...
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  • Are There Tie-Down Ratchet Straps I Can Use On My Trunx Rooftop Cargo Box For Extra Security?
    We do have tie-down straps for added security when mounting your Trunx Rooftop Cargo Carrier - 9 cu ft - Black # TRX44FR or Trunx Rooftop Cargo Box - 18 cu ft - Black # TRX34FR to the roof of your 2021 Jeep Grand Cherokee. I recommend getting Erickson Sliding Ratchet Tie-Down Straps w/ Safety Hooks - 1" x 14' - 400 lbs - Qty 2 # EM97JR which will suite your needs well. I have attached demonstration videos for you to check out.
    view full answer...
  • Trunx Rooftop Cargo Box that Can Fit Cargo that Measures 39x12x11.5
    Due to the taper on the sides of the front of the Trunx Rooftop Cargo Carrier # TRX44FR it would not fit your cargo, so you'd need to go with the larger size part # TRX34FR.
    view full answer...
  • Recommended Cargo Box for 2019 Toyota RAV4 That Doesnt Obstruct Roof Antenna
    In order to use the Thule Motion XT # TH629706 on your 2019 Toyota RAV4 you're going to need 47-1/2" from the center of your front crossbar to the crease where the roof and the hatch meet. However, it's going to be substantially less than that when it comes to the antenna, so using a long box like this likely isn't going to be the best solution because you're likely going to see some reception issues if it's covered. I recommend considering the Trunx Rooftop Cargo Box # TRX34FR, since...
    view full answer...
    Image 1 for
  • Durability Of SofTop Roof Top Cargo Carrier
    The Advantage SportsRack SofTop Rooftop Cargo Bag # HE3021 bag can be mounted and secured to the top of your horse trailer. That being said the bag is not waterproof per 0:40 of the video and water can get through the zipper potentially so these factors could cause the bag to not be ideal for all the time, permanent use. The bag may be more ideally used and then stowed away when not in use as it could wear down in the elements. An upgraded bag like the Rhino-Rack Rooftop Cargo Bag...
    view full answer...
  • Compatibility of CAM-Locks and Thule Boxes
    The CAM-Lock cores like part # CTC-CAMLOCK-18M-2874 are designed for the Trunx Rooftop Cargo Box, part # TRX34FR. As such, I cannot say if they will work with your Thule box or not. Thule has their own line of lock cores for their products. If you let me know which Thule core you have or which cargo box you have, I can help you find the correct replacement core and key.
    view full answer...
  • Will SportRack SkyLine XL Cargo Box Fit 2018 Chrysler Pacifica With Factory Crossbars
    We do have a cargo box that will work for your 2018 Chrysler Pacifica with the factory roof rack, but according to my research, the SportRack SkyLine XL Cargo Box # SR7095 will not fit. A cargo box at a similar price point which I can confirm will fit is the Trunx Rooftop Cargo Box # TRX34FR which will fit crossbar spreads from 22" to 31" but will require drilling new holes in the bottom of the box to get the U-bolts to mount to your Pacifia's crossbar spread. Like the SkyLine, the...
    view full answer...
  • What 16-Cubic Foot (Or Larger) Cargo Box Fits My 2018 Audi Q7?
    For a large cargo box for your 2018 Audi Q7, I recommend the Thule Motion XT Rooftop Cargo Box - 22 cu ft - Black Glossy # TH629906. The Thule Motion XT will fit crossbar dimensions up to 3-1/2 inches wide and up to 1-1/16 inches tall. The Thule Motion XT has the largest cubic feet of any cargo box we carry. In order to determine if the rear hatch of your vehicle will fully open without hitting the box, I recommend making sure that the measurement from the center of your front crossbar...
    view full answer...
  • Recommended Roof Rack and Roof Box for 2020 Mini Countryman with Raised Side Rails
    The Yakima FlushBar Crossbars - Raised Side Rails and Tracks - Aluminum - Black - Qty 2 # Y00456-2 and Custom Fit Kit for Yakima FlushBar Crossbars - Raised, Factory Side Rails - Silver # Y00158 you were looking at will do a great job for your 2020 Mini Countryman with raised side rails. Yakima roof racks are good looking and durable, so they're a great choice on just about any vehicle; the FlushBar crossbars also help reduce wind noise that less aerodynamic bars create. I recommend adding...
    view full answer...
  • Will The Thule Vector M Roof Cargo Box Fit My 2021 Mazda CX5 With Factory Roof Rack?
    The Thule Vector M Rooftop Cargo Box - 13 Cubic Ft - Titan Matte Gray # TH613200 will fit your crossbars just fine on your 2021 Mazda CX-5. Keep in mind, in order to allow your rear hatch to open properly there must be at least 47-1/2" from the center of the front crossbar to the line where the roof meets the hatch. It looks like your vehicle should have 48" from the from crossbar to the hatch so it should work find but it will be close; I recommend measuring to verify. In regard to...
    view full answer...

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Info for this part was:

Employee Andrew K
Test Fit:
Andrew K
Employee Jameson C
Expert Research:
Jameson C
Employee Jacob T
Video Edited:
Jacob T
Employee Chris R
Video Edited:
Chris R
Employee Daron K
Edited by:
Daron K
Employee Brian T
Written by:
Brian T
Employee Aidan B
Video by:
Aidan B

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