I got my Thai license about one year ago. The test is difficult. There is the issue of bad translation, but also many of the questions have nothing to do with driving. There are a number of question about various drugs and there effects.
I got my license by taking a course at Honda Safety Park in Chiang Mai. It's a driving school primairly for motorcycles, but they also have a couse for a car license. There several throughout Thailand. They have a large pool of test questions to help you prepare. I don't think I would've passed if I hadn't taken the course.