About a year ago I did a thread with a tongue in cheek project to try and clean up the cloudy and stained headlamp lenses on my 02 car.
For a couple of quids worth of Colgate it was worth it and the results were pretty good.
They did tarnish a bit after a year so I did them again using the same toothpaste. But I made a big mistake by using a household washing up sponge instead of clean cloth.
This resulted in micro scratching the whole headlamp surface of two lenses. A big DOH ! It didn't look good.
So I needed to find another fix.
While looking for something else motor related on youtube I came across a video showing a retail product that seemed to work like magic on restoring cloudy and stained headlamp lenses.
No crookery in the video it looked totally genuine and very effective.
The product is under the brand name of Meguiars and its called "PlastR X"
a one step restoration product.

Yeah I know people might think "here we go...." but this works astoundingly well and far better than Colgate

I learned about Meguiars as a favored brand from the BMW 5 series owners club who swore by their products so I already knew they are excellent quality.

I paid £15 on eBay for the standard 475ml bottle and I already had some clean stockinette for general bike/car cleaning. Yesterday I did the job using the "PlastR X". After washing down the headlamps with warm clean water and then drying off the whole front of the car using paper kitchen towels, I masked off around all the paintwork around the four headlights using duct tape with the bonnet open and leaving the bonnet open. You must avoid contact of the stuff with paintwork.
Using the clean cloth I already had and applying the pale blue thick liquid to the cloth first and then polishing up small areas at a time and turning the cloth and adding more liquid as you do when polishing. I took my time and spent maybe 5 or 6 minutes per lense and could already see how it was cleaning up underneath the polish residue. I applied more elbow pressure to polish out the bad bits which you can still feel and hear they are rough as you polish them. Even before the polish residue was dry I just wiped it off with the same clean cloth and polished them up. On the two worst lenses I did the a repeat of the process just on the bad bits again.

As I was finishing up and removing the masking, my little lady came out to the front of the house to see how it was going on, she was intrigued to see how good it was or wasn't. She was VERY surprised and I think her words were OMG ! I had already stood back and looked and I was very impressed.

The £2 Colgate fix was very hard work for a reasonable improvement and lasted about 1 year at most.

However the PlastR-X fix is very good ! Several steps up from Colgate.
I paid £15 for the Meguiars product and I used less than 25% of the bottle on four headlights to achieve outstanding and clear results. It doesn't look brand new but about as good as it can get for minimal effort and cost.
I just sorted my concerns about the car failing its MOT test next year on dim headlights due to the clouding and stains.

I'm going out in the car shortly when it gets dark to see how much the clear lenses improve the nighttime visibility.

http://www.meguiars.co.uk/

The product:

 

Test drive at night was excellent apart from one thing.
Considering the lenses were fogged due to my faux pas using a kitchen sponge which must had grit in it, anything would be an imprivement.

I have became concerned recently about the headlamp alignment.
The lights were quite dim for obvious reasons and they seemed to be too low on dipped beam. Long story short I parked the car at night facing a brick wall at a local shopping centre and tried the dipped lights and it the left hand dipped beam is low, too low it seems. That's kerb side in England.
However the right hand dipped beam seems OK. Having read up about the adjusters failing on the forum, I knew that was a possibility.
In the same spot facing the wall I used the headlight angle adjuster knob on the dash. Below and to the right of the steering column.
Using the knob slowly to "in theory" move the dipped beam up and down it is apparent that the right hand headlamp is responding but the left hand headlight is not, it doesn't move at all.

Using the main beam headlights they work fine and have a good bright light, but the left hand main beam looks quite a bit lower than the right hand.
That's over a distance of perhaps 15 to 20 feet from the wall.

I assume the left hand dipped beam needs the screw fix as a cheap fix?
But what about the left hand main beam? Is that lower position due to UK rules? I thought it was just the left hand dipped beam that is required to be lower, but not the main beam?

The car is OK to drive at night but with cars MOT in Feb next year I'm looking ahead.

 

Main and dipped beams share a common housing. Adjusting one will adjust the other. In other words, fitting the screw-fix to raise the dipped, will raise the main somewhat, as well.

 

Buy the adjusters off ebay, split the headlamp, and problem solved.

 

Yes they are easy to bake and take apart. The EBay guy has metal repair studs which are much better than stock. Then you can clean and polish BOTH sides of the lens before putting them back together.

Maybe even consider some new bulbs?
My original HID 12 year old bulbs still worked fine but the new ones were noticeably brighter.
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Thanks very much guys for the useful info.
I was thinking of the DIY screw fix but having checked out a couple of "how to" vids on YouTube splitting the headlamp units and fitting new adjusters, I've decided to go with that option because it retains the electronic adjustment. It also means I have a chance to clean inside the lenses too.

 

Clubairth1, yeah I swapped the standard bulbs for direct replacement xenon bright white bulbs as soon as I got the car. Same wattage as OE but much more light. These are not HIDs buy the way.
But still good to have the brighter xenon bulbs on our main roads which have no cats eyes anymore and we now have non reflective lane markings which you can't see at night when it's raining.

 

I recently acquired a 2003 S, 4.2 well maintained with 127k. The one item that needed attention was headlights. I spent $16 for a lens restoration product, attached the drill and away I went. Less than an hour later, I was astonished at how well it came out. Purposely scratching my headlights with various sandpapers didn't give me a good feeling, but in the end it was amazingly effective and very satisfying as I stood back and admired my work. Don't hesitate, give a try.

 

The problem with that approach is your internal adjusters are most likely broken and if not be assured the plastic is now very brittle and old. Mine crumbled into small pieces when I opened the lights. It's just a material problem and no head light can escape it.

Do you have HID's or the regular lights?

You do understand that polishing them is exactly the same as sanding them just with a finer grit? So depending on the level of damage you may never get them cleaned up unless you use a rougher grit of sand paper.

My HID lights seemed to get dusty inside as the years went on and there is a vent with a rubber hose on each light and I think that is where the dust comes from? Not real sure?
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My 2005 S-Type's headlamps are glass so I am lucky not to have to deal with any cloudiness. But my wife had a 2000 Lexus RX300 that suffered from this issue. 12 or 13 years ago there was a tip on the Lexus forum to vigorously scrub the cloudy headlamp covers with the bleach-containing bathroom-cleaning product called SoftScrub. We have always used that product to scrub our shower stalls, bathtubs, and sinks. So I soaked an old cotton diaper in water, grabbed our bottle of SoftScrub, applied a generous amount to the wet diaper, and vigorously scrubbed the RX300 headlamp covers for 15 to 20 minutes using multiple applications of the product. By the time I finished, those covers looked almost as good as new. From then on for as long as we owned that vehicle, I scrubbed the covers annually to keep them clear....

No idea if this will work on cloudy S-Type headlamps but if you have any SoftScrub handy, it is surely worth a try....

 

Jon89 I think you need to check but no S Type that I have seen has glass head lights?
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If my headlamps are not glass, they are the closest substitute to glass on the market. They certainly look, feel, clean, and remain crystal clear just like glass does. They are not the factory headlamps - they were replaced in August 2009 (along with nearly every component up front) after my car was front-ended by a careless driver in an F-150....

 

This is the video that convinced me to try some.
I do not know how it works, it must be a chemical or some nanotech thing but whichever way it is, it works well.

 

I used the Meguiar's headlight kit, involves 2 stages of wetsanding with polishing, then protectant. I was completely blown away at the results.

The second pic is the headlight cleaned and the first wetsand stage which gives the cloudy results. My headlights were terribly cloudy and somewhat yellowed.

 

They will go cloudy again unless some sort of UV protection is applied. I did mine twice before I installed EXPEL film.

About $60. Adds impact protection too.
https://www.ebay.com/itm/XPEL-Headli...haIeUo&vxp=mtr
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