:faint: After the test drive I said to the sales guy, 'I definitely want this car' ooopppss...
You are the customer, you hold the money and they want your business at the end of the day. Just dont go in with an 'I definately want an A3' attitude as they will see that and become much harder to haggle with. Tell them you are keeping your options open and blag about cars of similar class (eg: VW Golfs) saying how they are offering you X car for Y amounts, can you match/beat the offer.
I normally shoot for a 10% discount of list price but it varies depending on how much your car cost and how much extras you are adding to the car, I managed to get 11% off a new A3 S-Line last monday but it will vary from dealer to dealer.