[KevinH1990]

I started with a speaker upgrade and then added a six channel amp from a 996. Here's my upgrade path:

1. Added rear speaker - I used the Harvey/PNP kit that you can find on eBay.
2. Replaced dash speakers with Infinity Kappas
3. Found a six-channel amp on eBay and replaced the stock 4-channel amp
4. Swapped the CDR-220 for a Traffic Pro. I don't think this made much of change in the sound quality since the Traffic Pro is very similar to the CDR-220. The reason I made this change was that the Traffic Pros were on sale and the net cost was relatively low after I resold the CDR-220. My CDR-220 was having cosmetic issues due to peeling buttons.

Mike - Here is a good tutorial on installing the rear speakers: http://www.pelicanparts.com//techarticles/box_rear_speakers/box_rear_speakers.htm