Lot's of people driving with no insurance, which means unregistered too. But the basic liability insurance required to register a vehicle only pays for medical, no property damage. However the limits on it are pretty low, thus the about 700 baht per year cost. 80K baht for injury, up to 500K baht for death or permanent disablity, 200 baht per day if hospitalized but no more than 20 days.