I've lived here only 13 years but have had a Thai driver's license the whole time. Obviously, you haven't actually lived here since you would have one too. I'm assuming you do what so many tourist get by doing and that is slipping the policeman the standard 500 Baht for his troubles.
If anything goes wrong, and you are renters, you have much less invested and you can easily walk away. If you are an owner and lease your land many problems can come up and the civil courts are of little help, especially to foreigners.