At times when I come to a stop, I hear a buzzing/rattling sound coming from the engine bay, it sounds like it comes from the rear of the ending, close to the firewall. And it only happens sometimes, I can be sitting at a light, foot on brake, and it just starts buzzing, then goes away maybe 5-10 seconds later, then starts up against randomly. It is totally independent of idle speed as well, when it changes between 600-850 or so it makes no difference, it can buzz at both RPM's. My car runs just as strong, but sometimes the 1-2 shift takes a little longer than it should, and a few weeks ago I hit the rev limiter in first gear before it shifted...either possibly spinning or slipping, but I don't slip up hills or on high speed runs. I was wondering if there was a possibility of a loose bolt somewhere? I'd read some posts about the TC on built auto trannies, but can this happen with a stock car? I have a 1996 TT with 60k miles, an RMM DP, and an avc-r and BCC set at 1.10bar.