Granted, i know your car is an F30. I suspect it is the same story that i give for an E90 below.
Only cars getting factory alarm are properly wired to add the alarm system components. E90 runs wiring through the head liner and other very difficult places to disassemble. Prior to 2009, all E90s had the wiring so adding the system was simple. But after a certain build date, this all changed. I researched this when i found a 2011 w/o alarm. It was going to be $1500 labor plus parts to add the alarm. So, i walked on the car and found another with the convenience package which included the alarm system.
Last edited by BB_cuda; 01-22-2013 at 06:48 PM.