It's likely a fake plate due to a MO Statute: // Trucks with a GVWR of 12,000 pounds or higher are only required to have a front plate, under the assumption that the rear will be covered by something being towed. Note that the GVWR is the weight capacity of the vehicle, not the actual weight of the vehicle, so a truck still qualifies to only use one plate even if the owner never intends to pull a trailer. For reference, I think some of the more powerful models of F-250 might hit that GVWR, and all of the F-350s and F-450s do. //
Hadn’t even noticed that one 😳