i think a lot of it has to do with motorhomes having two different parts, the box from the RV manufacturer and the motorized chassis from the auto manufacturer.
twice the possible warranty issues, along with the motorized chassis issues probably more costly.
Dan-Retired California Firefighter/EMT
and Zoe the Wonder Dog(R.I.P.)
2016 PrimeTime TracerAIR 255, pushing a 2014 Ford F150 SCREW XTR 4x4 3.5 Ecoboost w/Max Tow Package