For the past year, I hear a loud rattle when I accelerate from a full stop (like at a stop sign or light). It only rattles for a few seconds, but it's embarrassing; sounds like an old hoop-dy! I don't hear it at all while driving. Dealer said, after checking into it, that it's a "body problem" but couldn't tell me what part of the body is causing it. To me, it sounds like something is being hit by the drive shaft. Remember putting playing cards on your bike spokes (showing my age, here)? It's the same kind of thing; but NOT cool! Any ideas?