I'll simply put this a bit differently, the problem installing an aftermarket HU with the Bose system is that many people forget that amps have two inputs, high (amplified by the HU) and low (essentially non-amplified - RCA out). The Bose (Clarion) HU sends a non-amplified (low) output to the Bose amps. If you "just" replace the HU, then essentially you are now sending a high level (amplified) signal to the amps. Doing this "feedbacks" to the deck and damages it, sooner or later. The appropriate way to install an aftermarket HU into the stock Bose speaker system is to purchase an High to Low converter.