I am seriously pissed off about this. Normally I buy the Volkswagen washer fluid because it's not heavily concentrated and can be mixed with water plus I like how it smells. Recently, the little washer fluid warning light came on in my car and after procrastinating for a while, I finally got tired of seeing it and ran over to AutoZone, picked up a $1.99 jug of washer fluid and threw it in the tank.

Cut to last week when I had to use the washer on a quick trip to Northern California. I washed the car today and found that the fluid has etched/stained the black plastic cowling at the base of the windshield. It won't wash off and since it was in the upper 90s and low 100s when I was in Redding, I fear the damage may be permanent. I have since drained the washer tank and flushed it with clean water pending my next chance to get some of the good stuff.

Any ideas? Here's the damage....

 

Looks like mineral deposits from the fluid .. Have you tried straight white vinegar or even IPA?

Thet VW stuff is the best .. trouble is the dealer up here doesn't even carry it ..

Love how it works and especially the smell.

Old VW owner lol ...2003 Passat.

 

If white vinegar or IPA doesnt work i would try a light steam.