Had the same issue. it's not the windsheild. you need to have the dealer do a software update. That should solve the issue. I had thought my HUD only worked at night -- until I brouhgt mine in for a steering wheel movement update, after the software update was conpleted, it also made the HUD visible during the day.

__________________
4.8|Sport Pkg|Prem Pkg|Cold Weather|Nav|PDC|Comfort Seats|Nappa Leather|Convenience Pkg|Rear Climate|3rd Row|HUD|SAT Radio|HD Radio|Dual-Monitor Rear DVD Player.