The usual measure of aerodynamic performance is the coefficient of drag. As a measure of the slipperiness of the shape, that's fine, but it isn't exactly relevant to consumers.
"Nice car, how much aero drag does it cause per frontal area square foot?"
- No one
More relevant for comparisons would be area * C_d. Or something like "brake horsepower needed to mix air at 60 MPH". That number would be immediately comparable to rolling resistance, cabin electronics, and numbers for other vehicles with similar interior space.
Consider, for example, that motorcycles have awful coefficients of drag, because it's such a complicated and messy surface that air flows over. They have great mileage, though, because of the size. A larger motorcycle might have a smaller drag coefficient but more drag.
So what is the frontal area going to be? I read somewhere that it's about 20 square foot, which is what you would expect of a small car. Fair enough, in that case the comparisons to Model 3 etc. are reasonable. It would also make the math work out in terms of battery pack size and estimated range (0.1 kWh/mile).
(In a recent interview though, someone mentioned that the vehicle has the drag of a 12 inch cube flying on the road. In that case, and assuming 20 square feet, the C_d would be 0.05. Which it obviously isn't. Maybe he meant to say 20 inches, or he only accounted for the body and excluded the wheels, or something.)
Anyway, drag at a given speed is more interesting to me. At highway speeds, specifically, because that's where the big energies are normally spent, and where efficiency and range matter.