I have an 02 c230 coupe that I just purchased. when i start the car it makes a clicking sound inside the dash that lasts about 2 min and sounds like from behind the radio. It started out only doing it occasionally and now it is every time i start the car. If i turn the car off pull the key out and then stick it right back in and start it again it stops. Please help its driving me crazy but i dont want to go in the poor house to get it fixed.