reply to sparks
Re: [Help] How to get f@%$^%@ing Rain-X off my windshield! +1
This is a mild abrasive, almost like a polishing compound, which is used by wiper test labs to get off the residue that is normally deposited over time from the wiper blades themselves.
Other suggestions for using comet or sandpaper are too abrasive, and using solvents is probably not good for the car.