Over the last few months I've noticed the top of our other Fabia have become slightly cloudy or scratched. I've read and tried a few easy methods, toothpaste and Autosol, but to no avail. Washing and claying makes no difference.

 

 

 

What's the best way of removing it, without buying brand new ones?

I do this as a little sideline.  Basic process is wet sanding, compounding, refining and sealing.

 

Originally top, sanded (still wet) bottom

 

 

Top sanded and dry, bottom polished

 

Did the neighbours A4 recently.  She was chuffed.

 

 

Just how do headlight lenses get into that condition? Between 2000 and 2013, I owned four Fabias (two at a time)...two were garaged and two were outside 24/7. They were washed (carefully!) at similar frequencies and all the lenses were like new when the cars were sold. Why did they survive unmarked?

Just how do headlight lenses get into that condition? Between 2000 and 2013, I owned four Fabias (two at a time)...two were garaged and two were outside 24/7. They were washed (carefully!) at similar frequencies and all the lenses were like new when the cars were sold. Why did they survive unmarked?

Go back 30 years and this problem didn’t exist. That was because headlights were made from glass. Glass transmits light very well and is easy to clean but has two drawbacks in automotive applications: It’s not readily formed into the complex geometries demanded by car stylists, and it’s easily broken.

To get around these limitations, car manufacturers switched to a type of plastic called polycarbonate. Polycarbonate has great impact resistance, transmits light almost as well as glass, and can be readily formed into complex shapes. But it is easily scratched and, like most plastics, deteriorates when exposed to ultraviolet light (the same UV rays that let us tan).

To overcome these weaknesses, polycarbonate headlights are given a UV-resistant coating. This lasts for a number of years, but grit and dirt thrown up from the road, plus frequent washing and that darn UV light gradually wear it away, exposing the polycarbonate to the elements. Once this has happened, the light takes on that cloudy appearance.

Well said Alan

I do this as a little sideline.  Basic process is wet sanding, compounding, refining and sealing.

 

Originally top, sanded (still wet) bottom

 

 

Top sanded and dry, bottom polished

 

 

Looks far better. What products did you use, Grits/compound? Was it done by hand or machine/drill?

I have used the product shown below with good results. It comes with fine wet and dry paper and some cream in a tube. Start with the fine wet and dry paper and then polish it afterwards with the cream. The cream must have a very fine course compound in it. After a bit of elbow grease, the headlights on a previous car of mine came up really clear. It cost about £10 from my local auto shop.

 

Xerapol plastic polish, Acrylic Scratch Remover.

Go back 30 years and this problem didn’t exist. That was because headlights were made from glass. Glass transmits light very well and is easy to clean but has two drawbacks in automotive applications: It’s not readily formed into the complex geometries demanded by car stylists, and it’s easily broken.

To get around these limitations, car manufacturers switched to a type of plastic called polycarbonate. Polycarbonate has great impact resistance, transmits light almost as well as glass, and can be readily formed into complex shapes. But it is easily scratched and, like most plastics, deteriorates when exposed to ultraviolet light (the same UV rays that let us tan).

To overcome these weaknesses, polycarbonate headlights are given a UV-resistant coating. This lasts for a number of years, but grit and dirt thrown up from the road, plus frequent washing and that darn UV light gradually wear it away, exposing the polycarbonate to the elements. Once this has happened, the light takes on that cloudy appearance.

Well, I was aware of all that, thanks....but it doesn't explain why some lenses end up like the ones in the original post, and some (mine after 8 years and outside 24/7) looked like new. Is it mostly down to careless/careful washing? My "outdoor parked" Fabia was even parked with headlamps facing South - getting their full share of UV.

I don't think Jim will mind me saying, but his is not the best kept Fabia . His has galactic miles as well 

Looks far better. What products did you use, Grits/compound? Was it done by hand or machine/drill?

 

The first grit depends on how bad the lens' are.  On the Audi A4 I started with 240 grit.  Seriously!   Admittedly it was quite light but I needed good cutting power for minimal effort.  The marks from the 240 were removed with a lot of 1200 grit, then 2000, then 2500.

 

Then all by machine I used a compound with a 2" wool pad, then a lighter polish on a toughish 4" foam pad, then a going over with a 6" pad.  Finally sealed in with Jetseal 109.  I'll only use the "good stuff" if paid for it.  Jetseal is good enough in short term.

I don't think Jim will mind me saying, but his is not the best kept Fabia . His has galactic miles as well 

 

If you're talking about ours. It's 53 reg with 97k miles. Being Silver it doesn't get washed that much, certainly not as much as my Black one.

It only needs to be in sunlight for the headlights to go, mileage is sort of irrelevant - It's merely where it's parked during the day.

 

In "theory" a garaged car will never suffer, but it has to come out at some point.

If you're talking about ours. It's 53 reg with 97k miles. Being Silver it doesn't get washed that much, certainly not as much as my Black one.

. Did not know you had changed Jim