I recently purchased a 1992 Z-28 with 10,123 miles from the original owner. The car was only driven on dry sunny days so it is in showroom condition. The car has the Delco Bose Gold Series radio. When I got the car the right side, front and rear speakers did not work. I sent the radio to M&R electronics for diagnosis, they said it is fine. They recommended replacing the speaker amp, but it should be done in pairs due to potential differences in volume output. I replaced the right front speaker amp, now it works. They were correct about the differences in volume, so I replaced the left front speaker amp. The right rear will only work if the volume is wide open, so I assume the amp is weak. Replacing the individual speaker amps is a pain in the rear no to mention costly. Has any one else had this level of amp problems ? I am to the point of buying a 4 channel amp and by passing the individual amps, can this be done and what are the watch-outs ? Very dissapointed in Bose engineering, assuming they have some !