I still need to find out about on how to register my vehicle in New York, what do I need?
You'll need a letter from the leasing company giving you permission to register the vehicle in NY, a power of attorney from the leasing company that authorizes you to register the vehicle, and the signature of the leasing company officer in box 3 on the Vehicle Registration/Title Application or on the Registration Authorization.
I don't think I paid sales tax for all of the lease payments. What do I do?
The process will be the same as if you hadn't paid any sales tax at all. You'll have to provide DMV with your lease agreement and fill out a Statement of Transaction at NY State Department of Tax and Finance. The sales tax for any existing lease payments you have will be paid to DMV.