Some U.S. state laws forbid driving around with a scratched or dirty number plate because the numbers can become illegible. If you drive with damaged number plates, you may be issued a citation and must replace the damaged plates at the Division of Motor Vehicles in your area. Number plates consist of a thin piece of aluminium that you can easily bend by hand for a quick repair.
Straighten out as much of the bend of your number plate as you can using your hands. The flexibility of the plate allows you to flatten it with your fingers, which prevents adding more damage.
Flatten the number plate edges gently with pliers. Try not to scratch the plate or paint.
Place a piece of thick metal under the crease of number plate.
Tap the crease gently with a small hammer until the crease flattens and disappears. Take your time tapping and make certain you do not leave scratches or dents.
Clean your number plate using warm water, a soft cloth and mild detergent. Stronger cleaners can discolour the aluminium plate. Do not use abrasives like steel wool and scouring powder--they could scratch the aluminium surface and remove the paint, according to Extension Specialist Emeritus Anne Field at Michigan State University.