You actually can register it in another state, as long as your insurance company knows where you reside and operate it. Case in point: people who live in pa mostly but still have a house in ny. They split their time, but for federal and state tax purposes 51 percent is in pa. Do they need to switch their plates to pa, as they have more than one car and often just take the bus to go between. Do they have to have the pa car with pa plates? Or visa versa? As per Geico rep, the answer was no. You tell them which car resides where, and they rate your insurance where you have the car. The problems as you suggest , are interesting. U-Haul rents trailers, none are registered in states which have anuual stuff, even if the trailer is stuck in another state. In NY, the trailer is covered by the vehicle towing it. They have no requirement for insurance. (unless you wish to get insurance). Annual registration is based on weight. It isn't too bad. Just inconvenient.