I would like to keep the stock speaker and amp in my '93 touring, but replace the head unit with an aftermarket one. Is anything required of this other than a wire harness to match the stock harness to the OEM unit? I have the Mazda universal wire harness from "Turbowire" which looks like the right one according to the Bose wiring diagram. My OEM head unit has line level outputs, which I assume the Bose amps expect, so no problems here right?

 

yea you should be fine.