I'm in the same position and after some research it worked out cheaper to buy a car here. As an example: BMW offered me 16% Euro discount and 14% company discount. They did tell me that they would offer anyone walking off the street 16% Euro discount and an added 7% dealership discount. This is on brand new cars. Not sure about VW, but Mercedes has similar deals. Some more info is here: New car vs used car
Let me know how you get on!