I've only had my 08 E92 for a week. It had about 1000 miles on it when I picked it up (it was a demo, got a good deal on it). Since I picked it up I put 200mls on it and had it serviced for the 1200 mile break-in thing. Now about 200mls after the 1200 mile service I noticed a tin-can kind of ping coming from the rear somewhere. Only does it when I first accelerate or brake slightly (20-0mph), but doesn't do it every time I accelerate or brake though, it's pretty random and even the distance between pings is random when it does do it. I barely noticed it at first earlier today when it started but now if I roll down the windows when it does it it's pretty loud. Sounds a LOT like a pop can is dragging along the ground behind the car or under the rear driver's side wheel. A thought something was stuck under it but I don't see anything. I looked as best I could without having jacks to lift it up but still nothing. Another guess (pure random guess) is maybe a rock or something flew into the tail pipe and is rattling around in the muffler? Any ideas? The car dealers are closed here till Monday morning. Any help to put my mind at ease would be great, even if it's bad news at least I would know what it is as it's driving me crazy and making me very concerned. Especially since I'm out of town and have to drive back tomorrow, about 180 miles.