[tomhoward]

Some guys I know built a full-sized car, with the engine built with Lego and powered by compressed air.

https://www.youtube.com/watch?v=_ObE4_nMCjE

[protomyth]

There was an actual car project in India to develop a compressed air powered car https://www.downtoearth.org.in/blog/air/compressed-air-vehic...