kerrys914,
I do not have the BOSE, so I cannot help you with the amp. In regards of the speed signal, I think you will not have it at the BOSE radio. Audi sends this signal through the CAN bus to the radio. My 2002 Audi had it at the instrument cluster. As far as I know since 2003 you need to get it from the ABS.
KBiggZ,
My symphony radio had brackets riveted on the side, so no chance to just take them off and screw on the AVIC
Since I am a mechanical engineer and have access to a tool room, I will built something from scratch next weekend, but I assume a double DIN cage should f