So I installed the factory alarm on my 3.0si this weekend. I followed the instructions Bill M posted on BF.c. Hood install was fine but I found out that the installation for the M model is DIFFERENT than the non-M for the siren portion of the install. Instead of installing the siren under the rear cover of the bumper, it goes behind the right wheel well. Thought this might be useful for anyone who purchased the factory alarm in light of the new pricing. The coupe alarm typically goes for $120 but if you enter the part number directly, it can be purchased for less than $40. I'd get on this before they realize the connection and adjust pricing!
Part Number: 65730302424
At Tisher for $37.60 if you enter the part number directly
Or $120 if you look for the alarm by drilling down parts listed under the Z4
http://www.trademotion.com/partlocat...catalogid=4462
Instructions for M-coupe:
http://forums.bimmerforums.com/forum...d.php?t=913979
Instructions for Non-M:
http://www.unofficialbmw.com/images/6115EN.pdf
Instructions for pre-facelift Non-M
https://www.bimmerfest.com/forums/sh...4&postcount=11