Stumbled upon this product in the Eastwood Co. website and bought a kit. The kit inlcudes the Rhodite powder compound and a thick felt polisher buffer that you will have to connect to your variable rotary tool. Recommended speed is from 600-800 RPM only.
You basically mix the rhodite compound with water and apply it to the windshied/glass. You also constantly spray water while buffing the windshield.
The product effectively removed all sorts of minor scratches left by the wiper, all acid and water marks, and leaves an impressive sparkle in my windshield.