What's the procedure for getting a new one?

Go to the transportation office and tell them: “Baikabkee hei pai Krup”
They will issue a new one. If you do have a copy on paper or picture of your lost one helps in the process.
No police report required. Don’t forget to bring your passport and house book.
Pay the fee, wai and off you go.

12 minutes ago, siamcrut said:

Go to the transportation office and tell them: “Baikabkee hei pai Krup”
They will issue a new one. If you do have a copy on paper or picture of your lost one helps in the process.
No police report required. Don’t forget to bring your passport and house book.
Pay the fee, wai and off you go.

Any problems ask the young ladies at the information desk just as you enter the transportation department. Couple of them speak sufficient English if your Thai is not up to it.