There was language in the purchase agreement that stated that if you cancel the order after a VIN has been assigned you forfeit the $2,500 deposit. There were some rumors that a revised version of the agreement eliminated this clause but I have not been able to confirm this. The reason it makes no sense is that nobody would forfeit the $2,500 to Tesla rather than taking delivery of the car and then immediately returning it to get 100% of your money back including the $2,500 deposit. So while in theory Tesla has the right to keep the $2,500 on a cancelled order, in practice it makes no sense for them to incur the costs of letting you keep the car for a week and then bring it back for a full refund.