I suppose Theoldman should know if anyone should.....
I've been thinking about this a lot lately too. The thing is the car dolly is so much less to rent and in my case to buy, than a full trailer. There's ways around the sway issues and such but I have to admit I'm also hesitant to drag my car around over all the bumps and humps one encounters on the freeways. Depending on the state... some stretches of interstate are just plain rough!