Unfortunately, not legally. He can be held to the contract. He entered into a binding contract to pay the full contract price when he paid the £13k deposit. Like a futures broker or a banker he 'futures bought' but came unstuck. There is a case law precedent on this, actually concerning an Aston Martin. Johnson v/s Hersham & Walton Motors, Kingston County Court, nineteen ninety something. That case partly hinged on the substantial size of the deposit paid and the fact it had been put through the selling dealer's VAT books. This made is part of the purchase price rather than merely a 'deposit' to hold the car for the customer.