you dont need them to register but you do need them for inspection... that is if you have a wind shield
so now you are wondering why would one do that........well because they might want to drive it and take a chance on getting just one ticket instead of two... registered, Insurance, but no inspection..
you can probably get buy with driving a lot with just antique plates as long as you dont drive it ever day to work and the same cop is waiting for you...lol