Re: Windscreen cleaning
there are 3 different grades of Clay, as some have said about soft clay, i would dare say this is incorrect you need a clay more of an medium or heavy duty clay to remove over spray.
1) LIGHT BAR CLAY BAR for regular everyday use. For the Car enthusiast or professional detailer working on higher end vehicles, or new vehicles that need a light bar that will never scratch the surface. This scratch free ultra-flexible elastic bar is a huge customer favorite that truly works great for all paint finishes.
2) MEDIUM BAR CLAY BAR- for light to medium jobs with moderate oxidation that you can really feel. Great for light to medium oxidation, and paint over-spray removal. able to clean 95% of all surfaces and remove environmental fallout to prepare for buffing and waxing.
3) HEAVY DUTY BAR-CLAY BAR use for heavy oxidation where time is the real issue. Great for business professionals that need the surface smooth prior to polish or buffing. Ideal for medium to tough jobs and larger amounts of paint over-spray especially if the over-spray has been on the car for a long time.
but you wil also need a lube or you can make your own.