Can’t see where you’re going? We tackle restoring the faded plastic headlight lenses which are becoming a common problem on modern classics.
Al though I’ve always loved old cars, I’m generally all in favour of new technology: in my modern everyday car, I’m happy knowing there are a dozen airbags protecting my family, while the hands-free phone, ABS brakes and digital radio all make for a generally pleasant trip.
Just sometimes though, you wonder why a particular idea ever made it to production at all and whether it is in fact genuine progress or a case of reinventing the wheel. A prime example must be the advent of the plastic car headlight lens. No, it won’t shatter when hit by a stone but neither is it bulletproof either and while it might be lighter than a glass equivalent is there really anything in it?
The answer quite possibly is that it’s cheaper to mould a plastic lens to the complex shape required to suit a particular front-end style than it is to tool up for a glass unit and that’s the reason why plastic lenses started to become common in the late ’80s and early ’90s.
Modern plastics technology is clever stuff and when new you sometimes had to tap the light with a finger to determine whether it was glass or plastic, but throw in the effects of several years’ worth of road dirt and UV light and suddenly it’s all too obvious.
One problem which afflicted the earliest plastic headlight designs was a general yellowing of the surface which tended to colour the light output even if it didn’t restrict the light itself too much. Improved plastics generally had this sorted by the mid ’90s but the problem of road dirt scouring the lenses remained and is still a problem.
Many cars we now regard as modern classics sport plastic headlights or at least plastic indicators or sidelights and the list includes the early Mondeo, most VAG cars including the Audi TT and late ’90s Jaguars to mention just a few.
Many of these are now suffering badly to the point where excessively cloudy lenses will potentially be an MoT failure point. It’s not just older cars either: just look at the lights on the next MkV Golf you see and it’s quite likely to be going the same way.
For a modern car it’s simple enough to buy a pair of used lights when the problem becomes too bad, but on older cars where parts supply is an issue it’s not always that easy. There is however an easy way out and you’ll probably have seen headlight refurbishing kits for sale. With a bit of skill and patience though, it’s easy to do the job yourself with material you’ve already got in the garage.
Essentially the trick is to flat the surface of the light with abrasive paper and then polish it back to a gloss, much like you’d do with paintwork. The trick is not to be too heavyhanded with the polishing which will heat up the plastic lens too much. Here’s how we got on with the lights on our own Jaguar.
2 Our Mk1 Mondeo uses glass lenses for the main lights but the indicators are clear plastic and becoming dull. They’re just as much of a safety feature as the headlights and respond just as well to polishing. That condensation isn’t helping either...
1 Not only are these lights tiny but they’re noticeably pitted and dull after 123,000 miles and 16 years. The light output is truly terrible, despite better bulbs.