I have put it on the headlights before, when it was raining and the car was stationary it seemed to run off just as well as it did the windscreen. I can’t see there being any issues as they say it can be used on motorcycle screens.
I can’t get on with the stuff myself, no matter how much I clean the screen / wipers it always seems to smear. I don’t bother any more, I can’t bring myself to throw away the nearly full bottle I have though :roll: