Swamp Thing, first off, you don't drive a Thing at "high" speeds unless you have the top down and the windshield down (if you want bugs in your teeth)  

Seriously, there is nothing to really keep the windows from "flapping" but they don't really make that much noise as you're driving. Usually, the windows are just removed if the weather is OK but they will stay in just fine.

It just happens I have a good set of original windows for sale if you need some.

                                                                          :cool: