You may be able to get all of that functionality without spending $400 by coding. See these threads:
I had mirrors and windows and sunroof coded in my E92 but our initial attempt at doing the same didn't work on my E89. Going to get together with my friend who has the cable and software for coding later this week to attempt what's in those 2 threads.
2012 Audi R8 V10 6MT, Ibis White/Black with Red Contrast Stitching
2009 Z4 sDrive35i 7DCT, Alpine White/Coral Red [Retired]
2010 335i 6MT, Space Grey/Coral Red [Retired]