Like my MINI, one of my other cars has a rear wiper, and the previous owner was slow to replace the blade insert, and as a result the arm left a semi-circular arc on the glass. Any suggestions on how to remove it?

 

buff it out with a sander just kidding dont do that... ive never seen anyone remove or repair scratches in glass.

edit: google search found these,

http://www.essortment.com/hobbies/di...repai_sggt.htm

http://www.gtglass.com/

looks like kind of a port/polish technique

 

This kit should work well with what you described.....but if its deep enough to get your fingernail caught it, it may be too deep for this kit to work......

http://www.autogeek.net/glass-repair-kit.html

 

Careful with the scratch remover kits, they can cause a distortion in the glass. If yours is the back window it shouldn't be a big deal, but a windshield could be annoying at the least if it becomes distorted.

 

Eastwood has a couple of options

http://eastwood.resultspage.com/sear...w=glass+polish

 

I have seen some of these kits and if the scratch is light you can improve it but the only real solution for deep scratches is replacement.
However, if it is light using a polish kit could help.
Good luck and let us know your results if you use a kit.

 

Griots Garage has some great glass polish stuff available also.