As you probably have found, the cost to accomplish a factory upgrade' (ie components, drivers, missing wiring) surpasses the 'economically feasible' test... just replace with a high end audio upgrade. You could spend thousands on parts and harnesses, recoding, etc, and have an -at best- decent system. And be stuck with a car that your dealer will refuse to honor any warranty claim having to do with any aspect of the audio system (and pray you never have any battery/discharge issues)

The old days of 'change the amp and the speaker' are gone...IMO

A