One further suggestion: If you are using a trailer (and sometimes even if you're using a dolly), it can be mighty convenient to get a trailer hitch put on the car. That way, if you need to store the trailer and/or car someplace other than your campsite, you can tote it around a bit with the car as opposed to using the motorhome for that duty.
Most cars won't have any trouble pulling their own empty car hauler trailer around for a short distance at slow (campground) speeds. That's an entirely different usage scenario than pulling a trailer down the highway or toting it with a significant load...which may or may not be advisable, depending on the car.