Just joined and have a E46 320D SE Tourer.
I am upgrading the stereo and have already put in my old Alpine 7893R Head Unit and Dension Lite connection kit to allow iPod connection. Next was to install my Parrot CK3100 Bluetooth kit along with the steering wheel interface to allow me to control everything from the steering wheel.
I have now run all the phono cables from front to back of the car as I start to look at placing in my amps and subwoofer, along with working out how to install some decent speakers.
I'll try and post some pics as I go about my installs.