To remove a bumper sticker from a metal bumper, dampen the sticker with vinegar, lighter fluid, or nail polish remover. Then scrape the sticker off with a razor blade.
How do I get a bumper sticker off a car?
By Linda M. J.
Your car as most cars today have what is called a urethane clear coat over the paint. It protects the paint and give a shine to the paint. So you can either go to a auto supply store and buy a tool that fits on to a drill and will remove the sticker without damage to the paint. There are several companies that manufacture these items. Or you can go to a body shop, and every shop has these tools and they can remove it for you. It may cost a few bucks for them to do it. Some poster may have a home remedy but be careful it doesn't harm the paint. So try it on a small area that won't be noticeable.
Seasonal or political stickers on your car windows after the election can easily be removed with a single edge razor blade. Just slide the blade along under the sticker and it'll peel right off.