I forgot to report on this. I pressed the dealer to perform a TSB (technical service bulletin) fix for my HK rattles. The TSB calls for placing small velcro strips to wedge between the the rear deck vent and the deck. This causes the deck to push tighter against the rear window so it does not rattle. Also since they replaced my HK amp I'm only getting half the bass as before but from what I can tell is that the velcro fix did help. BTW, the parts were backordered and it took several weeks to come in.