I didn't want/need nav, but wanted a DD unit that would fill up the space where the stocker was. I also needed to use my Sirius hardware I had just purchased to go in my Jetta, but then ended up buying this Audi and decided to make it my daily.
Post install TIPS for the A4:
[*:1tdgiie7]Turn the illumination on the buttons to RED - it matches the interior lights very nicely.
[*:1tdgiie7]My A4 is an 2003 1.8T Quattro NON-BOSE - your may differ, so do your research.
Edit for shopping list:
Metra 70-1787 wiring harness
Metra 99-9102 dash kit
Metra 40VW53 powered antenna adapter
Pioneer ADT-VA133 double din install kit
Metra Audi/VW/MB (star type or OEM) stereo removal keys
Extra red, yellow, and black 16 g. wire
T-taps and butt splices
About 6 hours of time.
Install in an A4 was a little tricky, but nothing too bad at all...just needed to find the right wires to tap, and had to get the correct hardware. Something to remember is that the rear speakers and sub all run off of the OEM amplifier (which sounds great BTW) so remember to use the RCA plugs on the Metra harness for the rear speakers. Since they are already amplified, all they need is the low level signal from the head unit. The front speakers are not amplified, and need to be connected to the harness using wires on the harness.
To bypass the video I used a 3rd party relay from eBay. Do a search on eBay for pioneer avh-p3100dvd bypass and you will find a seller. It's around $30-$40 shipped.
On with the finished pics:


Please excuse the bad pics - it was too dark for a good exposure:













