Towing Issues: towing an expired vehicle, u haul trailers, tow dollies

Question
My boyfriend wants to tow my truck from CA to AZ with a car dollie but my truck registration is expired. Will this be legal? I have been told that all 4 tires must be off the street if reg. is expired. Do we need a trailer to tow this back to AZ? Please help. Thank you.

Answer
While I do commercial towing, I know that California and Arizona have some wild and confusing towing laws. Now for private people to use items like U Haul trailers and tow dollies to move their own vehicles, its hard to actually find the correct laws.  I did a quick search and did not find any reference. (I know if I had more time then it might be a better answer) but I would go the trailer route and have all 4 tires off the ground.  That way it will not cause any more problems.   

I do know that lots of un licensed / expired tag vehicles get towed, moved, or transported everyday but depending on how far out of date it is might also be a factor..