I was driving home with my wife this morning and heard a strange noise coming from the dash. It sounded like the noise made when you switch from interior to outside circulation. It occured every 30 seconds and we couldn't find what was causing it. I tried pushing buttons to see if either of the controls was causing it. Nothing doing. Noise was there for the 1 hr drive home. Got out of the car after parking it in the garage and I heard the noise again....coming from my pants pocket. Pulled out my cell phone and it went off again. It was my cell phone reminding me the battery was low.

 

I had a similar issue once. In my case, my car made a horrible clunking noise when I went around corners. I was worried about drop links or other suspension issues. It turned out to be a bottle of Arizona iced tea rolling around under the passenger's side seat. My son left it there. I'm sure the mechanic has told that story a few times before...