Selling my car but where do I register the sale?

Anyone have experience in selling their vehicle in Udon in a private deal? Do I need to take the buyer with me to the purple building out in Nong Soong (Land Transport Office) to register/transfer the title or is there another office in Udon that needs to become involved? I bought this vehicle (a Toyota van) new from the Udon dealer almost five years ago and it is free of liens or encumbrances.

You don't need to go to the Transport office in Nong Soong (Ban Hoy for motorbikes) with the purchaser, (although it might be advisable, as you will need to provide a copy of your passport & therefor trust the buyer with said copy )...
First step is to go to B2S stationary shop (top floor of the complex, just outside Robinson's), ask for 2 forms:
1/. San Yaa Sur-Kai (25 Baht)
2/. Nang Sur Morb Amnad (25 Baht)
Make sure the cashier rubber stamps these forms with the official emblem, I believe it's called a 'Garuda'.. (half bird/half man emblem)
If you are going to Nong Soong with the purchaser, you won't need the Nang Sur Morb Amnad form.
Fill in the forms together with the purchaser, & they can then do the transfer themself at the Transport office.

I just sold my car about 3 months ago. Had to have a Certificate of Residence to sell it also.

Thanks, Stevo. The complex is not my favorite place to shop these days but will be making an exception. Appreciate the info.

RAnderson, Certificate of Residence? Is this an Immigration form? Well, the vehicle was actually bought in my Thai wife's name so we will take her blue book copies and Thai ID, just in case. Thanks for that info, also.

Sorry, I just assumed it was in your name.