Tonight while watching a cop show (Speeders or Over the Limit), the idea of a police officer pulling someone over for not having a front plate confused me. I'm used to license plates being in the rear, and people sometimes sticking a novelty plate in the front (especially religious persons or sports fans). It occured to me that some states may require two plates, in the front and back respectively, and I looked the matter up on Wikipedia. It seems most of the US has adopted the front/back approach, which makes me wonder: what would happen if I drove my one-plate car from Alabama into a two-plate state as a tourist? ....and what would happen if I moved to a two-plate state? Could I just wait until my plates needed to be renewed to buy my new state-specific plates?