Can I leave and re-enter Thailand with a Destination Thailand Visa (DTV), or do I need a re-entry permit?

The Destination Thailand Visa (DTV) is ONLY sold as a 5 year multiple entry visa, <- that means from the date it's issued for the next 5 years it's good for you can exit/re-enter the country all you want and you will get a new 180 day entry stamp every time

You can't even BUY a re-entry permit once they see the DTV in your passport, as it is sold WITH the re-entry permit "built in"