Didn't realize it was so sensitive to that and don't know if they recommend against it on their site, but it put fine scratches all over the shield. That sucks so I thought I'd better pass on the info in hopes of preventing anyone else from doing it. I've used these scrubbers for years on my cars and never had an issue. Obviously certain kinds of plastics don't like it at all. Stupid move on my part. Just trying to get bugs off......