sQuba Submersible Sports Car --Rinspeed calls the sQuba the first real submersible car. Unlike military amphibious vehicles, which can only drive slowly on a lakebed, the sQuba travels like a submarine - either on the surface or submerged. The interior is resistant to salt water, allowing the skipper to drive into a lake or the sea. The only downside? It's a convertible.
I think the trouble is telling them what the project is about. People think you are mad. Once I started telling people it was for “an oil tank”, they started to take me seriously. Guernsey Submarine documents the building of a homemade submersible. You can also watch another K-350 in action, read about how to design them, or buy plans, if you're truly inspired.