A little over a year ago, Honda showed off its totally cool Project 2&4 concept . The super bare-bones two-seat sports car with a motorcycle engine is in many ways closer to a go-kart than a traditional car. That's not a complaint either, since it sounds like a blast. At the time, we assumed that it was just an outlandish concept without any grounding in reality, but a new patent from Honda has us second-guessing the last part. The company filed a patent for an automobile using a cast-aluminum backbone chassis. The first drawing (figure 1 ) in the patent shows just the chassis with a pair of seats, suspension, and four wheels. Although the patent says the frame could support just three wheels, or more than four. The layout shows an engine just behind the seats with power going to the rear. It's a setup that sounds fun on its own, and sounds even more fun when seeing that figure 4 shows a minimal body shell like that of the Project 2 &4.There are more interesting tidbits here, too. The cast-aluminum chassis is described as very light, stiff, and quick to produce. Everything else on the car is connected to it as well. Additional members for the seats, steering wheel, pedals, and gauge cluster, among others, all attach to this center point. The patent lists several advantages to this arrangement, and it allows for different seating configurations for either left- or right-hand-drive markets, or for just a single occupant. The frame even features provisions for inflatable roll-over protection, shown by items 110a, 110b, and 110c in figure 2.