to adhere to their backing board dries out. Like Oakley said, it's worse if the glue somehow gets exposed to moisture. Most times, though, it just dries out. I'm sure you could go to a detail shop and have it redone. Might cost some jack, though. You can try gluing it, yourself. Also we used to use staples. We weren't tying to make it look like brand new, though. If a customer asked us to just fix it so it's not in their way. We would use a staple gun...then spray it with spray adhesive and once it was dry, remove the staples.