OK, it seems like the info on the internet is confused. It seems to say you need an IDP to drive in Thailand, which basically means getting one from where you're from, or in the case of many on this forum, where you reside.
However, some websites have made it seem like you can get an IDP easily at DLT to solve the problem of someone like a tourist who wants to drive. In fact, the US Embassy website makes it sound this way.
However, according to what all of you have said, it's only for people with residence, a 5 year thai driving license, etc., to be used outside of Thailand.