How to remove "stains" / oxidation / bird crap type marks from windscreen

[dt4]

Any suggestions on how to polish out a sort of acid etch effect which is pretty much all over the windscreen
I have tried autoglym screen polish to no avail
Thanks

 

[whitenemesis]

This gets many recommendations

http://www.barkeepersfriend.com/car-care

I prefer Sonus Glass & Chrome Polish

Some use T-Cut or even toothpaste!

 

[television]

I use watered down T cut, it removes everything

 

[DanF]

its all here, go to the 5:00 mark and watch from there.

Very important to be wearing the correct gloves.

http://www.youtube.com/watch?v=-IjoKjwQEDI

I love this guy.