Excellent! Thank you for your detailed reply. This helps me (and probably others) a lot

Hi everyone, after reading a bunch of threads regarding FES and cheaper modules, I went for a relatively common Bluetooth Interface (http://www.amazon.de/gp/product/B006CFXX8S/ref=oh_o01_s00_i00_details). A quick test in my car showed, that I have no connection to the Can Bus. Expecting this, hence ...