30 days.
You Need to provide Malaysia Car Registration documents.
Car owner identifications.
After leaving Malaysia Immigration and Customs before entering Thailand Immigration, you park the car and purchase Vehicle Insurance valid for 30 days from Vendors just after Thailand Immigration and Customs.
You walk to clear Thailand Immigration with your passport. Thereafter you walk to the next counter to register for your Vehicle Permission to Enter Thailand (with all documents) at the Thailand Customs Office.
Easy process. Takes about 5 minutes.