I was driving down the street the other day and looked at the back window of the person in front of me. It looked like he had a bad tint job. Circles, discoloration, etc. Can't remember if he had a BMW or not. Then I noticed I had the same thing on my back windows. Is this some sort of temperature fluctuation thing or what? I turned on my rear defrost but it didn't seem to help and then forgot to check later. Does anybody here know what I'm talking about?

 

Yes I know what you're talking about. Its in almost all the cars that i've seen. All cars without tints. After I got my tint I dont see it anymore. Seen it in MErcedes, Toyota, MINI, Lexus... etc etc etc.

I have a picture of it on my car and on a 20 year old car. Talking about those tiny circles on the rear windshield?



Ok I dont have the picture of it showing on the E60 at the moment but I'll post it later...

 

I see this on all kinds of cars, especially when I'm wearing polarized sunglasses.

 

LOL, It's called polorized lens in your glasses.

 

You are Riddick

 

Ah ha! So it's my sunglasses? Yep, those little round circles.

 

Hey the circles are caused by the reflective heat / UV coating that all car manufacturers put on their cars. The coating is made more obvious by wearing polarized glasses, I can sometimes hardly see through the glass. Its completly normal though, the circles are their because the coating becomes damaged by the weather and heat.

Hope that helps.

 

It is not a coating, it is due the tempering process of the glass on toughened glass windscreens.

it used to make driving a car with polarised lenses in your shades almost impossible.

The development of laminated glass front screens put an end to it, but toughened glass is still used in other auto glass.

It is usually only noticed when the glass is angled, like in a rear screen, less so on side galss which is perpendicular to your eyes.

 

Hehehe I guess a pic of a 20 year old car does wonders here.