My present long distance vehicle is a 2006 Honda Civic Hybrid. While it is not "supposed" to have a hitch, I was able to find one to fit.
It has a 200 lb. tongue weight, and, 2000 towing capacity. I generally get close to 50 mpg while driving. I have used it to tow two motorcycles
on a heavy trailer from Las Vegas to Laguna Seca on a few occasions. MPG towing the trailer, right around 30. But, it screams it's guts out.
I was looking into the hitch mount rails that are being discussed here, and, for my use, even taking out the batteries, I would be over the tongue
weight limit of MY hitch.
I do valet parking, and, we have many guests with VERY heavy mobility scooters. With the weight of the lift and the weight of the scooter,
there does not seem to be any negative effect on vans, trucks, or SUVs with these in use. They are probably heavier than an S or DS.
Some of the hitch mounts have some pretty good weight capacities, and, even allow 2 motorcycles to be transported.
MAYBE two FXs or XUs, with batteries removed, but, would not feel comfortable with anything bigger
than smallish dirt bikes, or ONE DS, S, or SR. probably not with power tank. I used to race, so, have always had trailers. I like the Kendons
for weight and ease of use, but, very pricey. For once or twice a year use, a day at a time, the, U Haul route seems to be best. If you are going
to start doing track days, it may be 6 or more times a year, and, then, the U Haul becomes less attractive. Harbor Freight has trailers for under
$200 that should work. Lowes and Home Depot have similar trailers for under $500. There is always the option of going used and saving some $$.