Somehow people think that spoilers make cars aerodynamic. I have read many comments on here that downforce is drag.
Well, so is lift. NASA says that if we reduce the lift\drag on a plane at cruise, we drastically reduce the energy needed to propel it.
Popular Mechanics explains that the huge wings are only needed for takeoff and landing, but the X-57 uses the six motors on each wing to provide lift on takeoff and landing, larger motors on each wingtip to actually propel the craft, and until battery technology improves, "you don't need hydrogen fuel to power a fuel cell—you can use diesel."
"The energy density of Hydrogen is 120MJ/kg. The energy density of gasoline is 31 MJ/liter × 3.8 liter/gallon = 117 MJ/gallon." Gasoline is 29/30ths as energy dense as diesel, so diesel is closer to hydrogen.