Resolve to move on. “Political campaigns and straight A’s end at some point,” so the stickers you slap on a car to show partisan loyalty or parental pride might eventually need to go. When that day comes, clean the stickers and the area around them first, then grab a hairdryer.
Heat and scrape. Set the dryer on high and point it at the middle of the sticker, holding it a few inches from the surface, never on it. Once the middle gets warm, move the dryer slowly to the edges. By scraping at an edge with a credit card or your fingers, you should be able to start peeling the sticker away. Repeat heating and scraping as needed.
Reach for the cleaners. If the sticker’s residue proves stubborn, apply some tree-sap remover. Once the area’s clean, polish it with some glass cleaner or detailing spray.
Source: Cars.com