[mikiec]

Technically speaking..

If you get stopped for committing a violation they will check your plate number and make sure the number is assigned to you and the registration is valid. They then decide whether or not to ask you to add to the policeman's ball fund. BUT, they could be a pain in the ass and inquire as to whether or not the plate is legal. i have seen people drive around with card board plates to replace lost one's.

It is illegal to deface a plate, but I found nothing about a different plate with the correct number.