Don't think so. I think they'll only unlock it for you (after you mail it back to them) once it's used all 5 unlocks and you've returned the last tuned car back to stock. They can be "married" to one car at a time. Return that car to stock, get a "divorce" and you can tune a different car. It's then married to the new car. It won't work with the original car. You can do this 5 times - even if it's just swapping between the same 2 cars. Expend those 5 charges and I think you can send it back to get refreshed, but I've never heard of anyone actually doing it. Buying a used one you need to make sure it's: a) no longer married to an existing car b) still has charges left on it c) has enough charges left that you are happy with (most only need the one?) Probably just the way forums work, but I've never heard of anyone reporting back having success after having bought a 2nd hand unit. Have heard heaps with a new paper weight that bought one.