fastwheel, don't post if you don't know what you're talking about.
The green goblins are always something to worry about, no matter what you drive, or tow, or where you go. I've been stopped by them 3 times, had trucks impounded, trailers towed.. its not fun, and not cheap.
Its true, the car has to be registered and insured to be towed with a dolley. The fact that it will be in parts would DEFINATELY get you pulled over if they see you, and will get impounded without question.
U-haul also has the flatbed trailers, Its probably a good time to start asking your friends if they want to go on a road trip with their truck..
and as for the safety ratings.. Legally, you would be over the limit. But structurally for the vehicle, it would be able to take it. My truck is a half ton, but I tow 7000 pounds with it sometimes without a problem. The fact you'd be on the highway, it would do just fine. Its the stopping and going that would hurt the car/tranny.