At one time or another, a sticker has probably ended up on your windshield or other auto glass. If you removed a sticker, but the sticker left behind a sticky residue, with a little work and troubleshooting you'll be able to get rid of the sticky residue from your auto glass.
#1 Rubbing Alcohol
Take a paper towel and soak it I some rubbing alcohol. Then, take the paper towel and use it to dab at the edges of the sticker. Keep dabbing at the sticker until you have saturated the entire sticker with the rubbing alcohol. The rubbing alcohol will make the sticker soften, and eventually crumble. Once the sticker has softened, take a razor blade and use it to gently remove the rest of the sticker. Use a clean paper towel and wipe away the remaining residue on the glass.
Keep in mind that rubbing alcohol has a strong smell, which is why it is best to keep things well ventilated while you work. Keep the car door open, or roll down the windows, as you work.
#2 Use Some Ice
Another way to get rid of the residue is with some ice. Take an activated ice pack and hold the ice pack on the sticker. Keep the ice pack over the sticker for about five minutes. This will allow the ice pack to cool and moisten it. After that time has passed, take a razor or something else that is sharp, start at the outer edge of the sticker, and work inward as you remove the sticker.
WD-40 works for so many things, including removing old stickers from your windshield. Just spray a little on the sticker, let it sit for a couple of minutes, then take a damp cloth and wipe across the sticker. The sticker should come right off, without the need to use a razor blade to scrape off anything.
#4 Regular Window Spray
Finally, you can use regular old window spray. Spray it on the sticker, allow it to soak for a few minutes, then see if you can gently pull the sticker off. You may be able to remove most of the sticker on its own; for the parts that don't come off right away, use a razor blade.
The key to removing a sticky sticker is to get the sticker wet enough so that you can remove most of it easily. Then, go back over the area very gently with a razor blade, removing the remaining sticky residue, then clean the area again to make sure everything is gone!