My M5 comes prewired for an alarm. I called Momentum BMW in Houston and they will install it for $852. This is outrageous considering a good after market system will cost half that. I do like the idea of the plug in factory Alpine alarm system. Does anyone have any experience with this type of thing and suggestions. Also, my driver's side rear view mirror does not tilt downward when the care goes into reverse. It is suppose to do that isn't it? It says it should in the manual. Can anyone help me out with how to go about fixing this. Thanks in advance,