No questions here. Just sharing some experiences.
I have the 2006 Sport with the Sunroof/6-disc stereo package.
I like the look of the factory head unit (although the display sometimes is very dim when humidity is high until the A/C is run a bit.)
Speakers --- have been an adventure.
1 --- Regardless of what Crutchfield has in their database, you can put some fairly deep 6X9's in the front doors. The Polk db 6x9s fit well with the spacer provided with the speakers. I cut a slash in the vapor barrier just to make sure the woofer could move efficiently.
2--- There is a cross-over somewhere in the factory system that passes the highs to the dash speakers and lows to the doors. If you upgrade without rewiring, you'll get no midrange and highs from the front door speakers. (I'll fix that with the amp install.)
3---Rear door speakers. I don't recommend spending alot of money here. The shallow-mount Polk 6.5s don't put out much volume. (Perhaps a full-depth 6.5 with a spacer would work better?)
4---Amp. I've bought an old-school Rockford Fosgate (62.5W RMS x 4) off ebay. I love the older RF amps!
5---Harness for stereo. To add an aftermarket amp (with factory deck) it appears that your install is simplified by buying a harness made by PAC. AOEM-CHR2
for the 2006. This gives you RCA-outs and an accessory wire to hook up to the amp.
Waiting for the AMP and harness to come in the mail!