The headlights on my 2006 Ford Focus are getting "foggy," to the point where the light emitted is greatly reduced. I have tried an aftermarket headlight cleaner from Canadian Tire that works in polishing/ buffing out the foggy portions. In fact, afterwards the headlights look close to new. However, this only lasts about a month before the problem returns. Other than replacing both of my headlight units, do you have any suggestions that might improve it? I am currently just repeating the process monthly. – Peter in Oakville, Ont.
As you are well aware, plastic and even glass lenses dull after continued exposure to flying particles and the nasty stuff in the atmosphere.
This is especially true with plastic lenses. When the industry switched from the mandated round or rectangular glass headlights decades ago, it allowed car designers the freedom to include headlights in their work. This quickly led to a vast variety of sizes and shapes, easily done with plastic that can be moulded to almost any shape. The lenses can be almost any imaginable shape but the hardware behind them is pretty uniform.
The plastic lenses have a thin layer of protectant film on them when installed, but this is worn away over time by the constant bombardment from small particles thrown into them by vehicles ahead. Anyone who travels regularly on gravel roads or roads where salt or sand is used in winter knows the damage that can be caused to windshields, the leading edge of the hood, side mirrors, headlights and other areas exposed to this bombardment.
The weakest of all these are headlights – partially because they stick out further and are lower, but mostly because they are "softer" than the other surfaces made of metal and glass.
There are numerous kits available that allow you to restore the surface of these plastic lenses to a like-new condition. But how long they stay that way depends on whether the system used includes a final step – the application of a protectant layer, something that will deflect damaging materials and effects of UV rays, yet not influence the passage of light through the lens.
One of the Sylvania kits has such a synthetic final film as does the 3M Lens Protectant Kit with Protection. You can also apply a thin plastic film like those used to protect the surface of cellphone and PDA screens such as that available from a company called XPel.
A coat of wax, applied frequently, might help, as will adding a car length to the following distance on roads and in conditions where vehicles ahead are throwing up a cloud of dust and debris.