I think the BeamNG people should add a map editor. I'm thinking something like a free fly, first-person camera with drag-and-drop blocks, props, models, etc. Anyone have any other UI ideas? (I'm not a BeamNG developer, I just think they should add a map builder and want to help with ideas)
You have to be in windowed mode, Lalt+enter to jump between fullscreen and windowed then press f11 It is pretty much straight forward after that, just don't touch the buttons you don't want to touch.