anyone have trouble with their amplifiers on the harmon kardon system? i was getting some intermittent buzzing and thats what the dealer says he is replacing to fix it. also....while there i was informed of 2 recents recalls, 1 for a relay switch on the smg, and the other was some sorta reprogramming of the computer. I personally hadnt recieved anything in the mail in over a yr from bmw about these.