Originally Posted by Victor300E

I installed my pager/auto start alarm next to factory alarm module since I have to splice into factory wiring to save time. I had to run few wires to left drivers side to ignition switch. I think most convenient place for alarm brain would be next to factory alarm in passanger foot rest area under carpet. I did my friends BMW and we replaced Prestige alarm with autostart. His alarm brain was hidden behind the center console near center floor wents. Check near factory alarm module. I hope this helps and good luck
Victor