Recommended Baseplate and Wiring Harness to Flat Tow a 2021 Kia Soul LX

Updated 01/21/2026 | Published 01/18/2026

Products Featured in This Question

Roadmaster Direct-Connect Base Plate Kit - Removable Arms

(3377)

$575.00

Replacement Crossbar for Roadmaster Motorhome Mounted Tow Bars

(50)

$101.40

Roadmaster 4-Diode Universal Wiring Kit for Towed Vehicles - 7-Way to 6-Way Coiled Adapter Cord

(3247)

$188.24

Roadmaster Battery Charge Line Kit for Towed Vehicles

(1235)

$42.90

Roadmaster Falcon 2 Tow Bar - RV Mount - 2" Hitch - 6,000 lbs

(407)

$850.00

Question:

I would like to have base plates for 2021 Kia Soul LX with a manual Transmission. I would like to make the base plates match my Falcon 2 tow bar, Do I have to use the cross bar or can I connect direct. I think this is the Base plates 521643-5 is it correct? Also I would use RM15267 and RM 156-25, is it the right one for the Kia? Thank you

asked by: Rene S

Expert Reply:

Thanks for all the information Rene and welcome back! The Roadmaster Direct-Connect Base Plate Kit item # RM-521643-5 is exactly what you need for your 2021 Kia Soul with a manual transmission. It is compatible with your Falcon 2 Tow Bar item # RM-520. You'll be able to ditch the crossbar item # RM-067 because your Falcon 2 is going to work directly with the item # RM-521643-5.

The Roadmaster 4-Diode Universal Wiring Kit for Towed Vehicles item # RM-15267 you referenced, is what you will need to control your Kia's lights from your RV. It includes the 7-way to 6-way cable too.

The Roadmaster Battery Charge Line Kit for Towed Vehicles item # RM-156-25 will keep your battery from dying on your trip.

Do you already have a flat tow braking system? If not, I'll be happy to make a recommendation. I would just need to know if you want a portable or permanently installed system. If you do and you tell me what kind, I can make sure it's compatible with your Kia and let you know if you need any additional parts.

You can add this information, along with any other questions you have, where it says Add Comment.

expert reply by: Jerred H

Base Plate Kit
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Rene P.

1/21/2026

What is your suggestion for a brake system for my Kia Soul 2021 manual transmission . Thank you

Jerred H.

1/21/2026

@ReneP I recommend the Curt RVi Series Shadow 2 Flat Tow Brake System item # RVI94FR. This is a permanently installed braking system that is compatible with electric, hydraulic, and diesel motorhome braking systems The Curt RVi Series Shadow 2 item # RVI94FR is a proportional braking system that slows or stops your Kia with the same amount of force your motorhome is using to slow or stop. It comes with a convenient dash monitor that allows you to adjust the braking intensity and view the voltage of your Kia's battery with the included charge line kit. Using the Curt RVi Series Shadow 2 item # RVI94FR would mean you don't have to purchase the Roadmaster Battery Charge Line Kit item # RM-156-25 . Please note that it is recommended to install the Roadmaster Stop Light Switch Kit item # RM58MR with any permanently installed braking systems on your 2021 Kia Soul. This ensures your brake lights and turn signals work correctly when you are making turns and applying your motorhome's brakes.