I have brought 2 second hand cars, one in Bangkok, and one near Pattaya, both using the site one2one cars, both from "Tent" dealers, I have only good things to say, never had a problem with either, they have to keep their reputation, they are very good at detailing the cars they all look brand new, I always go by how many kilometers on the clock and not necessary the year, check to see if the service history is up to date, and if you notice any problems, like a worn tire point it out and the spare, jack and wheel brace is there, ask for an oil change too. Last one I brought was for the missus, and the dealer not only put it in my name for me (pink card/yellow book) but as I didn't want my wife driving it back from Pattaya, they delivered it to Koh Chang ferry bang on time the day after, not extra charge.