It's hard to convince customers that they don't need huge SUV or pickup truck to drive solo to work in the office. On top of that there is clear, design trend especially in pickup truck world to have biggest, most vertical grill that is possible. Moving such wall trough the air at highway speed is far from efficient. No matter how badly Fiat wants to sell cars like small and efficient Fiat 500, Tipo, Alfa Romeo Giulia etc. that can be sleek and good for environment, in USA they will mostly sell huge RAMs, Jeeps and muscle cars.