I'm not too familiar with BMW's, but graemlins/bsflag.gif
On any car I've ever seen so equiped, the charcoal cannister is component of the EGR system.
Components of AC systems: Compressor, Discharge Hose, Condensor, Liquid lines, Filter/Reciever/Drier, Evaporator, suction hose, Thermo Switch. That's it in a nutshell.
If you can, verify what he is telling you and then maybe we can better assist you.