[TiresOnFire]

I have both a 2015 435i and 550i, both with Head-Up Display (HUD) and I notice the windshield is both "gritty" and has the appearance of being lightly sandblasted when the sun hits it a certain way. I understand HUD glass is "different".
The issue is with getting it clean. I use a microfiber towel to dry the car and all windows, but on the windshield the microfiber towel "drags" on the glass and leaves little "micro fibers" all over the windshield. It's almost like there's a light paint overspray on the window, if you can relate to how that would react with creating drag on a towel and shreading it slightly. I put a razor blade to the window, and there's nothing stuck to it.
This is true for both the inside and outside of the windshield, and true for both cars so I'm convinced this is just the way it is going to be with HUD glass. Tips on cleaning and thoughts as to why HUD glass is so different?
Thanks!

[NewM3driver]

I always have felt that the HUD was a distraction, and as somewhat of a purist I prefer to look at standard good old fashioned gauges and a clean window. I never knew the glass wasn't smooth. I HATE dirty windows, and that glass would drive me crazy.

[ezmaass]

Strange. I have HUD and my glass is both smooth and clear looking. Perhaps something else is going on - pollen, dust, or some other particulate of some sort in the air? Is it exceptionally low humidity? If I take my cell phone into a highly temperature and humidity controlled environment (like an IT data center), the glass will become gritty feeling. This also happens on some airlines/flights. I don't know what's going on behind the scenes, but it appears like some kind of reaction to the very dry and conditioned air - almost electrostatic like in nature. But if I rub my finger over the glass, it just feels gritty and dirty. Perhaps something going on at a grander scale with your car windshield.

Long story short, your glass shouldn't otherwise feel gritty or appear dirty.

[TiresOnFire]

Thanks for the thoughts. Yep, Arizona desert is certainly dry. We did just get some rain and the wipers did their job so I'll stop my worrying.

[wrickem]

Like ezmass I don't have any grit on mine either. At least once a month I clean my windshield and wipers with Goo-Gone to remove any contaminates then I wash it again with water though. Besides always having a very clean windshield, my wipers are silent and streak-free.