Well it's on in Chiang Mai if you haven't heard already. The police are doing the rounds & seizing unplated bikes. Produce your invoices & you will / won't get your bike back?? One rental shop has been asked to produce the green rego books for their licenced bikes 250cc+ to be checked. An unconfirmed rumour pay 8,000 baht & you get your bike back. Supposedly a stack of bikes have been seized, but I can't see where they are locked up (yet). So if you ride an unplated bike, then DON'T - for the time being, or you will lose it. My guess is Chiang Rai will be next, if not already. You all take care now, plus expect these crack downs to become more frequent & tougher.