Here's a new one I couldn't find in any threads. It started about a week or so ago (1000 miles on the car, a C). I put my key in and started the car up and heard a loud "pop" noise. At first I though, crap, a speaker just blew. (I had this problem on a previous car and the noise was similar but nowhere near as loud). Turned the radio on, everything was working and sounding fine. Ok... chaulk it up to an oddity. Next morning, before I even start the car, literally just get in and close the door...POP! Now I'm really confused. Each day since then (about a week now), as long as the car sits for a while (overnight minimum) when I first start it that day, I hear the pop. It has happened backing out of my driveway, going a bit down the road turning, going a bit down the road just driving straight. It only happens once though. The best I can describe the problem is it sounds like a cross between a speakering popping and someone throwing a good sized rock at your windshield. It is VERY noticeable and loud. (It scared my wife considerably and I warned her about it prior to that!) It seems to be coming from the front passenger side of the car, possibly near/under the dash. And again, it only happens at or shortly after the first start of the car, either in the morning or afternoon. The only common issue is letting it sit at least overnight. ANY ideas/thoughts/help!!!??!?