Hydrogen and electric spark.

An excellent mix.

BOOM!

 

I'm not sure it's what people "demand" but rather what CAFE regulations dictate... And they're only getting tighter and less forgiving to low(er) mpg cars like the RX-8.

Although getting decent mpg's in a fun to drive car isn't bad either. I had two corvettes. A C5 and C6 that each knocked down 30mpg inI a steady state highway cruise.

The point being, the days of poor mpg cars, even in limited numbers, is getting shorter and shorter. I'm of the opinion that if Mazda doesn't make serious improvements to the efficiency of the current rotary "state of the art" it's likely we'll never see another rotary car as we know it. And that would be a shame.

 

The world is not US-centric as most seem to think. CAFE regulations are just local laws to a car manufacturer.
The US has 310,000,000 people, Europe counts 740,000,000 and Japan 128,000,000. Do CAFE regulation really upset non-US car manufacturers? Not really.

I also find it extremely funny that the US has a place for both such regulations and high displacement, low efficiency gasoline engines in heavy, big *** cars.
We consider a bmw X5 to be "big", you see toyota rav4 cars but not many land cruisers or grand cherokees. A ford f150 will be laughed at here, a ford ka is considered a comfortable city car that also allows you to travel.
That's why the cx5 is doing ok while the cx7 failed to pick up... there's no place in europe for a 2.3l gasoline suv with 250+hp.

European and most japanese car manufacturers value other markets more than the US for this very reasons. Less nonsense and headaches to care about.