I have a flatbed car hauler trailer, though I don't use it with my motorhome, one thing to be very aware of is weight, mine is a TopHat brand 18 ft metal deck car hauler like the one shown in this link https://www.tophattrailers.com/catalog/product/car-hauler/all-steel-car-hauler/
It has a 7,000 pound GVWR, and weighs in at 2,505 pounds, meaning the heaviest load it can carry is 4,495 pounds, which is around the weight of a mid sized SUV (my wife's Jeep Cherokee weighs in a 4,290 when nearly empty). I am not sure what your towing capacity is, but nearly all gasoline powered motorhomes have a max towing capacity of 5,000 pounds, many / most diesel pushers built in the last 15 years have 10,000 pound towing capacity, though some have less.
Ike