Renewing the registration is not the problem. Renewing an inspection sticker is. A while ago, a former Hertz rep posted on the Hertz forum that in rare cases, a car will be kept for longer than usual, due to a lot of rentals with lower than average mileage. If its inspection needs to be renewed, and the car originally came one-way from another state, the agency might decide to sell the car, regardless of its low mileage, since it would be impractical and expensive to send it back.