Awesome Thanks for all the info.The antenna you can get here: GPS antenna FAKRA RNS-E For BMW Audi VW Mercedes NTG Comand APS Vauxhall Opel | eBay
Or this complete kit: RNS-E BOSE Navigation System Plug & Play Adapter Retrofit Kit for Audi A3 A4 A6 | eBay
Since you dont have steering wheel controls it makes life a little easier. Getting a quadlock connector form a junk car will also allow you to make your own kit but that can get tedious.
Do you have Bose speakers?