Hi, I had exactly this problem with my 4motion not so long ago. It took three visits to local stealers to eventually get it sorted... The problem was supposedly intermittent according to them as far as I was concernened when you took the key out of the ignition left the lights on and opended the drivers door the buzzer should have worked... it didnt and I had to sit a 'techie' in the passenger seat to demonstrate this for him to believe me. [V] Anyway long story short, eventually they sorted it under warranty... isolated it to a switch in the drivers door think... you will certainly not need a new dash, and also I don't think the Mk4 uses the same buzzer as for the Handbrake/boot open/ passenger door open sound, it is more of a hollow drone!!! I'm popping into stealers tommorrow ans will ask them to bring up the repair details for me. Soon as I have them will give you the proper answer. Annoying when u 4get to turn your lights off and your battery goes dead isn't it!!!![V]