All installed - piece of cake on my 335i! Gotta say, the siren is pretty damn shrill in a closed garage. heh
Everything worked like expected - no panic button, arm/disarm notification or hood switch trigger but doors opening and motion sensor worked - clown nose blinks. I'm good for now unless the dealer decides to change their quote for activation.
Also of note - like described above, I tested the alarm after installing the motion sensor in the overhead lamp compartment - no siren or hood switch. The clown nose worked straight away.
Someone needs to figure out a little resistor end-cap for that harness in the overhead lamp compartment and sell them for a few bucks for folks who just want the clown nose to blink - could be much easier than the Radio Shack PCB mod (as long as someone was able to figure it out of course).