How to install aftermarket radio in 2001 Audi TT Coupe:
The various parts include:
Alpine CDA-9820XM from www.hookedontronics.com ($228.00)
Metra 70-1787 wiring harness from www.lafayetteradio.com ($15.95)
Metra 99-9100 face plate from www.lafayetteradio.com ($10.95)
Metra 40-VW10 Antenna Adaptor (non-amplified) from www.lafayetteradio.com ($7.50)
Metra 40-VW53 amplified Antenna Adaptor (replaced 40-VW10) from Fry's Electronics - needed for AM reception ($14.99)
AI XM-2SAA XM Roof mount antenna from Fry's Electronics ($27.00) similar to Terk XMicro2
Alpine KCA-121B Male Right Angle Ai-Net to Female RCA Cable from Best Buy ($24.99)
Alpine KCA-420i iPod interface: http://www.crutchfield.com/S-4hsGQ0gVQV6/cgi-bin/ProdView.asp?g=227550&I=500KCA420I
Other sources of information:
KrusTTy how-to: http://forums.audiworld.com/tt/msgs/1346967.phtml
xlr8d how-to: http://forums.audiworld.com/tt/msgs/1203497.phtml