Buying A Car In Thailand
If you want to buy a car in Thailand, you should make sure that the car will be registered on your name at least when the money for it is comming from you. Therefore you need the following documents:
Copy of your passport, showing picture & visa page. (You need at least a valid Tourist Visa, to have the car registered on your name).
A Residence Certificate from the Immigration Office, showing your address. you can get this when you make your address notification at the immigration within 24 hours after entering the country. Once you have this certificate, make a few copies of it for later use, e.g. telephone, motorbike. You have to do this anyway, so there is no additional hassle.(download this form here)
Armed with this papers you go to the car or motorbike dealer of your choice and buy a car or motorbike. The shop will usually arrange all the registration stuff for.
Outside Bangkok it can take up to 6 month before you finally get your plate number and registration papers. But don't worry you can drive your car in the meantime with a temporary (red) plate number.
Now, when you bring your Thai partner with you, the dealer will tell you that it would be so much easier to buy the car on the name of your Thai partner. Then, if you deny, your Thai partner will probably be upset and not talk to you for a couple of days or so. It's best to go on your own when you buy a car or motorbike. So do not, under no circumstances buy or register a car on a Thai name, if you are the one paying for it. No exceptions!
If you are on low budget and you want to buy second hand from a Thai, make sure he paid the taxes for it, otherwise you will be presented with the tax bill for the last 5 years or so.