So, I'm installing a complete audio upgrade into my 8 - Kenwood KCA-R71FM controlling a Kenwood Music Keg MP3 Player and Kenwood KTC-SR903 Sirius Satellite Tuner. Along with a Basslink Subwoofer, Infinity Amp and a complete speaker replacement. All interfacing into the non-Bose HU using the PIE adapter.

The hardest part for me - running the freakin' 4 gauge wire from the battery through the firewall to feed the sub and amp in the trunk. I gave up on the big rubber grommet on the driver's side (US RX-8). Instead I finally discovered I could drill through on the passenger side, behind the washer fluid reservior. What a pain in the butt, though. Had to drill at about a 45 degree angle

Finally made the hole using a Dremel with the flex attachment. I guess I'm just not mechanically inclined, because it took me quite a while.

But the effort has been worth it - the signal from the original HU is clean enough to drive all the other stuff very nicely. I'm very impressed with Sirius - seems like they give enough bandwidth to the music channels while compressing the hell out of the talk channels. A pretty good compromise, I think.

Sorry no pix - maybe my daughter will let me borrow her dig. camera so I can post something.

You should try running dual runs of 0 gauge in this car..... Something totally worth mentioning is the ground return in this vehicle. It is piss poor. More than likely it is going to be necessary to ground to the battery. Electricity is an algebra equation, what you do to one side, you must do to the other. The ground is the most important wire by far and both RX8's that we have worked on, have had a really high resistance on the ground return, this in turn = SAS (smelly amplifier syndrome - ewwww.)