Thanks for reply...since post I found a shop that had just torn down a car with Shaker 500 system and he said: all speakers run through amp and crossovers built into amp so no way to capture full stereo signal for aftermarket crossover/components...so would not benefit from expensive aftermarket speakers. Would have to buy JL Audio device and another amp to hook between factory amp and aftermarket components. So, bottom line, would cost $750 -$1100 to install $300 pair of component speakers.