A roll cage is great.. provided you're wearing a helmet at all times. An unhelmeted skull and a solid steel tube do not make good friends. Race-style harnesses do a great job of holding the body in place but they don't allow the driver to lean forward, and leaning forward is important at intersections, toll gates, drive-thrus, and the like. Not only that but they usually obliterate the rear seats' ability to hold passengers.

My 1988 Honda CRX DX has more legroom than almost anything I've driven, and I'm 6'2". The CRX HF model Honda made got 50 miles to the gallon, using nothing more than a small, efficient engine and a very light chassis. I'd love to see what twenty years of technological advances could do with the same idea. Make the engine the same size, but more effecient; make the chassis the same size, and throw in some airbags. I know that all the bullshit safety legislation and crash testing means it would never happen, yet I can't believe that we couldn't get another ten MPG with a modern engine. Then, I look at the Smart car, which weighs two hundred pounds less than the HF but gets worse mileage, and I start to doubt it. *shrug*