Thinking of getting an aftermarket radio with Navigation, phone and backup camera for my 2008 VW EOS with the base radio with 6 cd changer (changer does NOT work. Does anyone know what is involved to attach the new back-up camera? Also, where do I locate the GPS sensor. Finally, does my car have CANBUS system. The instructions for installation are different if the car does or does not have this system. Any help will be appreciated.