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.
The chassis is cast with specific areas for mechanical components. The spine that runs between the seats is hollow so a fuel tank could be placed there. At the rear, the frame curves around an area for the engine, and it's shaped to allow cooling air to run over the powerplant. The patent says that it wouldn't have to be an internal combustion engine either; it could use an electric motor. We imagine the area for the fuel tank could easily be changed to accommodate a battery pack. The whole chassis is suspended by a double-wishbone suspension setup, though the patent again says that this arrangement isn't required.
Exactly what this chassis could lead to is tough to say. Certainly a mid-engine Honda sports car isn't impossible, especially since the company already builds a miniscule one by the name of S660 for the Japanese market. However, this doesn't appear to be related to the tiny roadster. Odds are we'll likely see technologies based on the patent show up in less obvious places. Perhaps more cast aluminum components will be found under the skin of future Hondas. But if this hypothetical sports car did show up as a production vehicle, we'd love to see it appear in the States as a three wheeler, a la the Polaris Slingshot. It could be classified as a motorcycle and sold through Honda's powersports dealers. Regardless, it will be interesting to see what, if anything, comes of this patent.