i have a 98 slk 230. the sound is all stock except for an Alpine CD shuttle i added later on. i admit i do listen to music quite loudly with heavy bass. After a while i started hearing a rattle/buzz from either the door or the speaker. its gets really annoying. what the hell is wrong with it? should the system be able to play what is OEM? its not like i have 2000 watts or anything its just all stock.