Background
Headlights have two primary points of failure: the bulb itself that typically lasts 500-1000 hours, and the plastic lens that slowly degrades over time. Bulb failure is obvious and the repair is simple.
Lens yellowing, pitting, or cloudiness is gradual and more subjective. While so-called lens restoration kits promote impressive looking results, much of the deterioration occurs inside the housing and can’t be fixed externally. Lens cleaning, even if done professionally, restores clarity to at most 66% of original spec based on independent reviews.
Headlamp lenses made of polycarbonate begin to yellow after about five years regardless of environmental conditions and further damage is caused by ultraviolet radiation (that is, sunlight) and road grit abrasion. This results in an increasingly opaque material that can decrease light output by as much as 75% according to the AAA. This poses a safety hazard as well as an appearance flaw.
Since the entire fleet of New Beetles is now at least eleven years old, all models would benefit from headlight replacement.
