The windshield used for a HUD is special. It is a made of layers and they are in a wedge type shape. I remember reading about it when I bought my car and thinking that I DID NOT want to crack a windshield. That said, we may all have the same (HUD ready) windshield I'm not sure. But I would check that out as well. RealOEM.com lists two windshields, one is for cars with HUD and A/C.... Good luck! HUD is very cool. I would upgrade to the hand stiched leather dash too, while your in there - WTH?
'07 650i Coupe - Black Sapphire Metallic
M6 bumpers, skirts & wheels
BMW M Cross Spoke Composite 101 Rims 20"
HUD, Comfort Access