I have an 04, but had the same issue with an aftermarket speaker in my driver's side door. Turned out to be a loose connection that eventually worked its way completely off the speaker terminal. I modified the connection to make sure it is firm, and the problem is solved. I'm not sure how much you can really do about the quality of the connection with the OEM plug on there, but you might be able to bypass/rewire it if your handy with a soldering iron.