Some say there's a little welder in everybody - the inner voice that compels one to melt steel with steel and fashion it into something magnificent. Okay, people don't really say that, but if you've felt the urge (or are finding it for the first time) to forge improvised driving and flying machines, I've got good news for you. There's a group working on a way to facilitate your back lot adrenaline junkster desires, and that game has just been Greenlit. They call it Homebrew.
Your garage is stocked with everything you'll need: structural bars and drive shafts, engines both internal combustion and rocket, et cetera. You're free to piece these together as you please, though there's no guarantee your contraption will work. It looks a bit like a more terrestrial Kerbal Space Program except you're out for a joyride instead of advancing science.
As is trendy these days, a pre-purchase will grant you full play access to their work they add new features (multiplayer is on its way!). If you'd like to scope it out without dropping some cash, there's a demo here. Should you find that digital recklessness isn't as properly exciting as the real thing, please wear a helmet.