I picked up a brand new Mercury Cougar company car in Illinois at the dealership in 1978 and the only plate on it was a cardboard plate with the dealers name and slogan. They said they would send me the plates in the mail. I drove all the way back to Pennsylvania with no problems until I got into a small town and a Barney Fife hick cop put the lights on me. You would have thought I had murdered the Pope by the grilling they were giving me, and the only way I was left go was I mentioned my Wife worked at that small town hospital and the cop knew her. I didn't move that car from home until the plates came in the mail. Pa has NO sense of humor when it comes to these things. Don Oh, and you DO NOT want to stick a plate from another car on there if it isn't registered to that car, or you might be making license plates. Cops now have those electronic things that scan plates at a fast rate and you might be arrested for vehicle tampering or some other charge.