Here in WA as Doug said no mandatory requirement when licensing. I have collector vehicle plates on my 69 Marquis conv't and now on the K1 (the K1 plate arrived Friday). I have been told by a law enforcement buddy if I get stopped with no proof of insurance that I am subject to a ticket (500.00 fine). I will research if it applies to some 2 wheelers (it did not to the scooter I sold to buy the K1). Sounds like the insurance lobby wants this bad.