I had front windshield sunflim on my cars ,have to say no matter how expensive or the brand or car when you encounter a road with no street lights & get an opposing vehicle with high beams you cannot even make out even the left end of the road(without sunfilm you have a chance atleast),but it gets the worst when night time driving in the rains,but you will love it during the day,dont go for the charcoal shades for the front unless you really want a gangsta look,the reflective shades or the more expensive clear ones from v-kool or 3m Crystalline will do well for the front windshield
& yes it reduces glare from the headlights ,but your distance of vision at night is reduced if your on a high way with opposite lane sharing the same road,but on separated highways where the opposite traffic is on the other side of the divider you can drive better & peacefully with the sunfilms i feel !