@Nick ******
this what hapoens when you drive a motor bike without an IDP
1. They escort you to a police station
2. Fine you Baht500
3. Give you a form which gives you 3 days grace to get one.
4. If you get stopped again in those 3 days nothing happens, they let you go.
5. After this 3 days, I guess repeat 1 thru 4. Did not drive after that.
Happened to me in Chiang Mai