Got '03 GLS Passat with manual climate controls. Wonder what it takes to replace it with Climatronic if possible at all? Parts #s, $? I saw that there are two different part # for the front panel depending on the headunit - single or double DIN. So I guess climate control units are at least the same size plus all wires must be there as well. So in ideal case it would be just to replace manual controls block... Has anyone done it?