You may remember Aptera from the 00’s. They developed an ultra efficienct car with a fuel consumption of ~240-360mpg(UK) by optimising the aerodynamic drag: Cd=0.15 compared to Cd=0.24 for the most aerodynamic car of 2010 (Aptera Series 2 - Wikipedia). Unfortunately they liquidated in 2011 before achieving mass production.
However, they’re back, with the benefit of a far more developed EV market and are hoping to produce a car which is more than twice as efficient as a Tesla. You can support them through their crowdfunding campagin: