I just installed a Bluetooth system in my 2001 M5 from these people
http://www.*********.com/e39.html and was REALLY impressed. I ordered the kit and within 2 days got it perfectly. The system uses all BMW parts that are the New versions. Think MKII to MKIV upgrade, when you think about ULF modules. Instead of having 4 versions the Bluetooth system has 6! I got the latest module you can get and it works really well.

The install was easy and directions were simple to follow even for someone like me.

I decided to put this post here, as I called ********* before and after I got the kit and they were so helpful to walk me thru the process. Everything was perfect and it worked exactly as it should. The system is really cool and has voice control of the car.