Last year Imoved from Pattaya to Chiang Mai with a vehicle I have owned for five years. Do I need to re-register the car up here, or can I leave the same plates on, renew the insurance, and just keep everything as it is?

Not sure what the law says, but I've been driving with a Bangkok licensed car in Pattaya since 2004.

Paid my road tax and compulsory insurance at the local LTO without a hitch.

Also been doing the yearly inspections locally after the car turned 7.

Just go to the C.M. Office, get new plates , they do em for you in an hour, less stops by the Cops i found.