Moving a VIN to another vehicle is ILLEGAL and can buy jail time if proven. I know if later I bought and paid a convertible price to you and found you swapped a VIN to a 4 door I would follow it through court to prosecute.
good point.... i wonder just how much of the car you have to have there to use the vin from it..... i guess it's all in the disclosure because you do want the title to match the vehicle's looks. but i'm WAY far off from that to worry yet :)