I have been turning the idea of getting a one-off steam vehicle street legal around in my head for a few days. Its driving me crazy, it is a problem that I can't solve by going out into the shop and actually building something, or working it out in my head. I want to build off of an existing, readily available vehicle platform, and run my boiler from wood, coal, or whatever burns, instead of gasoline or something like that, as most steam vehicles do. See, when the spaghetti hits the fan, i want to be the only guy in my neighborhood driving around. If I want to survive in a post-apocalypse world (or live simply, independently, and on the fringe, where I want to be) I want to do so by my own merit, and that is where my engineering skills come in. So, my idea was to take a simple, older Jeep, like a CJ, and start there. I want to mount the boiler in front of the driver and fireman, where the motor originally would be, with the firebox door accessable to the fireman. A CJ's flat windscreen is important for this, so the fireman would not have to reach too far to add fuel, especially while the vehicle is moving. The area ahead of the boiler, in the engine compartment, would be a water tank. Behind the driver and fireman, a supply of fuel, easily within reach of the fireman. at the very rear of the vehicle, a steam engine, connected by a short driveline and u-joints to the rear axle (which would be flipped backward). The vehicle would be a 1967 or earlier model, which does not require seat belts, and have hydraulic (not power assist) brakes, which were common back then, because, a steam engine is not constantly running, only when the vehicle is moving, so there would be no way to charge power-assisted brakes without adding another engine. So my solution to getting it street legal is to start with a vehicle that is old enough so that anything you do to it isn't violating any safety issues, as of the date of the vehicle's manufacture. Then, you could add any body you like.... hot rodders do this all the time. And is there anything illegal about steam power? Say I started with a '62 Jeep CJ... and when would I have to get my "62 CJ" smog tested?

Automobile boilers are actually quite safe, they hold a relatively small amount of super heated water and are designed to fail progressively.  This is compensated for by the fact they have relatively lagre burners that are modulated based on load which allows them to respond quickly to demand.  In the entire history of steamcars there is not one death attributable to boiler explosion.  Besides, in a small car vs. an SUV I'm toast anyway - this way maybe I can take the SUV driver with me!