Since our cars come with treated glass to shed water, might the acidic alcohol of Rain-X be detrimental to the coating with which our windows are impregnated?

Thanks for your insight.

 

all i know is Rain-X ate my wiper & the rubber trim around the windshield pretty good. i don't see the point of using it. i'd strongly suggest to avoid it.

 

Thanks! That's the type of testimony I need. Time to buy the blue stuff w/o Rain-X!

 

some car manuals will advise against using Rain X or the likes if the glass is treated with their proprietary coatings.

 

ThanX I should pull mine out and read it.

 

wondered why i went through damn brand new Windshield wipers.........crap you learn everyday.....

 

May sound weird but I just wax my front window and it seems to have the same effect as rain x.

 

Do you seem to notice a build up of film days later? I never thought to use wax but that would be my first thought....

 

I haven't yet tried on Cayenne but I've WAXed the front windshield on my BMW but didn't like it after few days, however, I like on the side & rear glasses & side mirrors though.

 

Never noticed anything out of the norm before I will keep an eye on it now tho and see if I do.

 

any recommended windshield washer fluid other than the ones sold by Porsche?

 

hmmmm,,, I've been always using Porsche (for Cayenne) or BMW (for 5series) but I've recently picked up a bottle of windshield fluid from Auto store for BMW and it has been just fine.

 

I use Stoners Invisible Glass. Sprays on and wipes off with a towel. Easy application with no streaks and water beads off of it as if it's wax. It was recommended in the concours section of another Porsche forum. A great product and easy to purchase. I buy it at Autozone.

 

there's a sticker underneath the wiper fluid fill that states 'don't use products that repels rain.'
rain-x probably eats the windshield rubber seal just as fast as the wipers.

 

I can vouch for Stoners. It is all that I use to clean glass and mirrors. Cuts through grease better that the other stuff.