Rain-X on BMW Windshield?

[NeilS]

Does anyone have experience using Rain-X on a BMW windshield?

I use it on my face shield (with Shoei's approval), and I find it very useful. Not only does rain roll off the shield more easily, but it makes it easier to remove dead bugs.

I'd like to do the same with my windscreen, but I'm unsure about the chemical compatibility with the plastic.

[deilenberger]

In the past I've heard of people having crazing of the plastic caused by Rain-X..

I use a product called "Rejex" - which is made to polish aircraft windshields. Cee-Bailey sells it under their own name also (same stuff - looks, works, smells the same, same container - different label.) for use on their windshields.

Bugs/dirt/bird-crap all come off much easier with a good coating of Rejex. It can also be used on your painted surfaces with equally good effect.

A Google should turn up sources for it. I'm still on the original 10oz bottle I bought about 7 years ago - and it has polished a lot of windshields (and faceshields) and quite a few cars and bikes. A little bit goes a long way.

[r1200rforme]

Plexus is another product that was developed for aviation and can be used on paint as well as windshields. Use a cloth instead of paper to clean and makes small scratches less visible. Good stuff.

[HikerGlenn]

Neil, don't do it! Rain-x might be good on your car windshield, but definitely not on plastic! I worked in a Honda-Kawasaki dealership for a couple of years and saw the effects on Rain-x used by the unknowing on their windsheilds. It will turn them white, even opaque white in a short time. I recommend Plexus as the only thing other than soap and water to spray on your windshield. It really helps repel water, damaging UV rays, and makes it much easier to wash off the bugs. Hope this helps-Glenn.

[NeilS]

I understand what you're saying, Glenn, but you can't generalize about all plastics. As I said in my original post, I wrote Shoei a long time ago and asked for their advice. They told me they've tested Rain-X on their face shields and have not found any adverse effects. I've used it on my shields for many years and found it to be true.

I've used Plexus on other motorcycle windshields and I think it's OK for removing scratches and such, but it doesn't give the super-slick water-shedding surface that you get with Rain-X. And Plexus is a polish, which means that even though it's very fine, it does contain an abrasive.

Maybe it doesn't matter, because I don't look through the windshield, and all I really want is the easy-cleaning feature. But I'd really like to know the answer with respect to the specific plastics that BMW uses.