Just bought a 2004 Touareg and I’m trying to upgrade the cd changer head unit for hands free Bluetooth. Most of the upgrade kits I’m finding a reference to on this site are from 2011, any feedback on the newer options? Barring that, how hard is it to shoehorn in a new generic double din stereo? Local store has a few nice options but I’m worried I’ll loose some functionality or cause damage to the system. Thanks!