This might be old news, but Audi are offering their own 'remapping' service. One of the guys at work has a 225 TT, and got a letter from his dealer to say that they are offering a remapping service which should give around 54bhp extra. It also said that it wouldn't affect the Audi warranty. Cost was £599 (can't remember if that's ex vat or not?). Not sure what the lease company would say, although they've always said to me that as long as the car is returned in the same condition it was delivered (subject to normal wear and tear) then they aren't bothered what you do with it. Wonder if they are going to start offering it for other cars?