I had the windshield replaced on my MK5 with OEM glass, because I talked to the used car manager at the dealer who valued it in trade. If you ever watch them appraise a car, you'll see them look for mismatched panel fit and color, and on certain areas where they usually tape off panels, running their hands over them to feel for rough paint overspray, and the manufacture's etchings on the glass to see if it's OEM. They figure if you used aftermarket glass you could have had a collision or skimped on maintenance. I asked my insurance company if I could pay the difference when a stone cracked mine, and they said I could request it. Probably because I had no claims, they approved it at no cost to me. Where I live, it's required to be included in policies and it's not charged against you if it's not intentional.