[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.