I have just bought a 2.0TDCi Zetec CMAX after 'commiting' my Mondeo Zetec S TDCi. It had 50k on the clock in 14 months and I paid nothing. They valued my mondy at £13,000 and got a late 53 plate ex demonstrator with 2K on the clock as a direct swap. They will only commit your car if you bought it new, so if its second hand or even pre-reg'd by the dealer, they wont commit your car.