I've used new razor blades, as 79malibu350 had suggested and also lacquer thinners. I've had good results with both.
A dull blade can infact scratch your glass.
Also, ultra fine bronze (or steel) wool will work as well. In fact that was recommended to me by a guy who is proficient in window tinting.
I'm sure the clay bar will do the trick as well. Normally I picture using a clay bar on painted surfaces, but I can't see why it wouldn't work on glass.
A dull blade can infact scratch your glass.
Also, ultra fine bronze (or steel) wool will work as well. In fact that was recommended to me by a guy who is proficient in window tinting.
I'm sure the clay bar will do the trick as well. Normally I picture using a clay bar on painted surfaces, but I can't see why it wouldn't work on glass.