This was stated about the key: "Folded into the base is a mechanical backup key, a flat metal blade in a hinged housing."

I own a BYD: this is not true. The key is not hinged; rather, the entire mechanical key pulls out when a small clip is unlatched near the top of the assembly (you can see it in the CT). I assume the circular hinge-looking mechanism in the CT is just a by product of the plastic/metal weld process.

Nonetheless: very cool tech demo!