Why do you recommend an external (non factory) AMP?
Isn't the built in amp of the Alpine CDA-9815 already more powerful than the factory amp?
I was planning on installing the new radio and just bypassing the factory amps. I believe I can bypass the amps by unplugging connectors and jumping some of the wires. For more info, see:
94 E420 - Amp wiring diagram
Willy