Below is a quick video of what my installation looks like. It's real simple to do. I started at the detector and started running wires. When I ran out of wire from the direct wire kit I used two butt splice connectors and added more wire as needed to reach the ground point and fuse panel.
On the fuse panel I used fuse 186. It is on the bottom row. Third from the left.
What you'll need.
You can buy this stuff where ever you want. Below is where I got mine.
Direct Wire Kit.
http://www.amazon.com/Escort-79-0010...words=fuse+tap
Fuse tap (add-a-circuit)
http://www.amazon.com/Littelfuse-FHA...words=fuse+tap
Extra wire
Several feet of black and red 16 gauge wire (I think it's 16 gauge). Just visit Radio Shack or the like and roughly match the size of power lead on the add-a-circuit.
2 butt splice connectors
You can get those at Radio Shack or any automotive parts store.
Tip...
Put the 20amp BMW OEM fuse closest to the prongs on the add-a-circuit, and put the 10amp detector fuse above it lined up with the red power wire of the add-a-circuit.
Any questions just ask.