I got my Hualingan units this weekend and it looks AWESOME but unfortunately it doesn't seem to be compatible with all 39, e53s out there. Mine is a 2000 e53 with DSP. I couldn't figure out if DSP is the culprit but I get no sound. The unit must send the wrong iBus message to my amp/dsp that blocks the sound. Is there anybody in Calgary willing to try it out. It is a plug'n play setup and it should't take more than a few minutes.