There is one campground I stay at that has tow dolly/trailer restrictions.
You may have it on site so long as it remains attached to your Motor home or if you un-hook it you have to put it in the "Trailer Lot" and pay the "Trailer Parking Fee".. My opinion of this policy is that it does not affect me since I tow 4-down.
And that is what I suggest for you.. Tow 4 down, But alas not all towed cars can be hauled that way.. But let me give you a few reasons.
First: To find out if your car can be towed 4 down with or without modification google REMCO TOWING and answer the 20 questions (closer to five) it will tell you.
Now: Towing on a dolly or trailer.. you have to get it all lined up and pull on just so, then strap it down, and safety chain it, then tow it a ways and re-check.
4 Down: I can (and in fact last hook up did) easily pull up 45 degrees off, Get it close and hook up.. Put it in neutral, make sure the parking brake is off, and Away we go.. Hook up is two arms pins and latch pins, two safety cables one elctrical cable and a breakeaway cable, took me longer to type it than to hook up the cables (Arms take a bit of work). Arms store on the RV when not towing.
The only problem I have had with this I'd have had towing a car on a trailer as well.
Different cars tow differently:
Some all you do is put either the transmission or transfer case (4wd with manual transfer case) in Neutral
Some you need to follow a procedure (Start, run through gears, put in neutral)
Some like the one I tow now I had to add a lube pump, I tow in neutral but the lube pump keeps fluid flowing so the bearings are moist (About 1500 installed).
Some like the one I used to have I put on an axle lock, this is very old technology that has much the same effect as breaking a half axle on a front wheel drive,, One wheel turns free, the other one turns the differential the trasmission is in PARK,
Some you put a device like that on the drive shaft (Rear wheel drive).
In all cases the cost is about 1500 dollars to modify.