Most car door panels are made of plastic, which can be difficult to glue. There are, however, a few tips and tricks you can use to get the job done. To start, you'll need to clean both surfaces that will be glued together. This will help the adhesive bond better. Next, roughen up the plastic surfaces with sandpaper or a file. This will also help the adhesive bond better. Now it's time to apply the adhesive. There are many different types of adhesives that can be used on plastic, so make sure you choose one that is specifically designed for bonding plastic. Apply the adhesive to both surfaces and then press them together firmly. Hold them in place for a few minutes until the adhesive sets. If you're still having trouble getting the two surfaces to stay bonded together, you can try using mechanical fasteners like screws or rivets in addition to the adhesive.