The main difference is that the BumpShox bumper guard was designed to be flexible and absorb impacts. Steel license plates can bend out of shape permanently rendering them useless. Unlike steel frames that protrude out and can damage other cars, the BumpShox is comprised of a foam rubber than will protect the other car. Also the BumpShox bumper guard will never rust. Since the front of a car is always being subjected to flying debris, steel powder coated products can easily chip and begin rusting away. Lastly, steel products are costly, while the BumpShox is reasonably priced.