Strange rainbow effect on windshield

[asian_xl]

The car was coated and tinted on the first week and I don't see this on other M3, I heard bad coating will end up with rainbow colouring. is there a way to fix it after a year?

 

[F@kegman]

I have a similar look after applying 3M film on the inside of the front windshield for heat rejection.

 

[freeAgent]

The car was coated and tinted on the first week and I don't see this on other M3, I heard bad coating will end up with rainbow colouring. is there a way to fix it after a year?

View attachment 623918

You could always try polishing the glass assuming it's due to a coating on the outside and not any tint that you may have applied to it (in which case, you can remove the tint).