Motorcycles have plexi/lexan windshields and no wipers...
You might take a peak at exactly how the windshield and windshield wiper law is written in your state. They can be very weird. Oregon for instance, requires a windshield wiper but does NOT require a windshield... Go figure.
Oregon also does not require a wiper be powered. It can be a hand crank wiper.
Research and take advantage of the individual state's poor law making abilities! I mean hey, if us car nuts can't take advantage of the loopholes, there's no point in them existing! If that doesn't work, a little electric gizmo one with a silicone blade over a clean lexan surface will get you thru inspection (sounds like anyway).
angela