For those that wanted to keep their stock head unit and MOST fiber optic system, I ran across this option today to run an after market amplifier and allowing you to run after market speaker upgrades:

www.mobridge.us/products/most-analog-pre-amp"]http://www.mobridge.us/products/most-analog-pre-amp

Unit will provide 8 channels of preamp output to run into amplifiers for better sound

If you really want to go crazy, get their DA-1 which gives 2 channels output add a DSP unit like a mosconi , arc audio or zapco unit and run an active crossover network to feed your multichannel amps clean controllable signals to your speakers.

 

Have you look at the Audison Prima AP8.9bit?

 

...but then you are still stuck with the cassette deck and the CD 6-pack, no blue-tooth, no Nav updates (for 01 anyway) and no MP3 music - unless you buy another adapter for that stuff too. You'll end up paying the same as a new head unit anyway.

 

It was an alternative for those wanting to keep things looking as stock as possible