Take this bit of information at face value and make your own decisions. A car guy I know says that taking your cars through commercial car washes accelerates headlight aging. Could be the chemicals they use, could be the mechanical brushing, who knows. I can't really judge since even thought I don't get headlight fogging my car stays in a parking garage (when I'm actually at the office) or in my own garage at home. I do periodically apply Meguiar's Headlight Protectant, but I don't know if that changes anything for me.