Thanks for the info- it is a 300te wagon 1990, and the noise is a pretty loud and dramatic sound of something seeming to "flop around" behind the front seats, in the center of the car, underneath. Flex disc is my buddy's guess. Occurs only under acceleration, usually in first gear before the automatic transmission shifts into 2nd. I am looking to sell the car but want to sell it in good working order for the next owner and this sound just began last week. I don't want to drive it down to the dealer, because I'd have to replate and insure it to do what is about actually an hour and a half drive each way, not 133 miles. I was only looking for mechanic recommendations in the area, but since we are talking about the car now, does that sound like something that could be the center bearing as was mentioned? Or more likely the flexdisc? I understand there are 2 flexdiscs on this car. Thanks for any feedback, helpful or not.