[TiltonBB]

You can register a car in New Hampshire as a non-resident. You will have to sign a document that states you have a vehicle registered in your home state, Florida.

Prior to the law change a non-resident could register a car in New Hampshire but it had to be "exclusively" garaged in New Hampshire. The interpretation of that was it had to be in state every night. I was told a local Town Clerk used to send the police to the homes of people with non resident registrations to confirm the vehicle was there overnight. That was prior to the law change.

261:46 Nonresident Registration. –
Notwithstanding RSA 261:45, the department shall register motor vehicles owned by individuals who are not residents of New Hampshire upon presentation of an affidavit by the applicant, on a form developed by the department, swearing that the vehicle is principally garaged or is regularly kept overnight in New Hampshire and that the applicant is the owner of at least one other vehicle which is registered and insured in the state of the applicant's residence.