I recently 'completed' this on my '01 E39 530i and overall things are working OK. However, I have a couple of small issues however that may be wiring related. I know there are a couple of MID retrofit threads on the forum already so hopefully someone can chime in with some info. I purchased the retrofit wiring harness (65129405409) and two wires went to fuse 25 & 44, and the other three went to the black junction box behind the glovebox.
The issues are:
1) With my all in one cassette/radio unit I had previously, I was able to turn on the radio after the car was switched off with no key in the ignition for up to 20 mins. Now with the MID, it will only turn on providing the key is in ignition position 1. I asked another owner and he said he was able to turn on his MID/radio with the key out.
2) Whenever I get into the car, I now hear the CD mechanism starting before I've even entered key in ignition (it sounds like it's trying to eject a CD but no CD is present). Is this normal? Sometimes the mechanism will even go twice. I was hoping it was normal but I asked another MID/CD owner and he says this doesn't happen on his car. It plays CDs perfectly so no issues there.
I've attached the instructions that I used and a wiring diagram I found on another thread for reference. Any information on this would be much appreciated.