> For a small wheelbase vehicle to meet CAFE standards it has to get an unreasonable 90mpg or the manufacturer gets fined.

Source? At least according to this source[1], a car with footprint similar to a Honda Fit only needs to hit 51 mpg this year, which it currently meets[2][3]. There are certainly cars that are even smaller than a Honda Fit, and maybe those do need to hit 90mpg, but the existence of cars like the Honda Fit proves that you can have CAFE compliant cars that aren't "beasts".

[1] https://en.wikipedia.org/wiki/Corporate_average_fuel_economy...

[2] https://hondanews.eu/eu/fi/cars/media/pressreleases/1523/hon...

[3] https://www.wolframalpha.com/input?i=+4.5+L%2F100km+to+mpg