I have a mere 280 miles on my new Shelby GT500. They were all exhilerating until last night while driving home at the speed limit. Cruising At about 2300 RPM in 3rd gear @60 mph, the car started making a loud baffling noise like I was dragging a large plastic bag. It went on for about 30 seconds and then became a milder rattle noise. I turned into a parking lot and attempted to recreate the noise but it was just a slight clacking sound only when in gear and then it went away. It sounded like it was coming from the tail-pipe but I am unsure. Nothing felt wrong and there was zero change in performance. It went on long enough to be real. I have heard of clutch issues relative to the flywheel with new Shelbys. It almost seemed like it was misfiring but like I said, there was zero feedback in acceleration or in feel. The best example I can come up with is that it sounded like a loud and prolonged fart...Sorry, but that is the best analogy I can come up with. Anyone have any ideas?