A few years ago I spent many hours researching this topic, including reading the applicable statutes in each and every state for which they were available online (then all but a few). The result proved conclusively that the statutes that apply to towing motor vehicles are not the same as for trailers and that a towed motor vehicle is NOT a trailer per the statutory definitions. I also made some personal contacts with law enforcement officers and found that many of them did not know or understand the law.
By all means be in compliance with the applicable laws, and beyond that with whatever solution in excess of legal requirements that makes sense to you personally. Do not however be mislead by misinformed opinions stating that requirements written for trailers apply to towed motor vehicles.
