In any case, what I think Commanderfish really meant wasn't frontal area, which would be much the same for every car mentioned, and isn't terrible relevant anyway with a smooth shape, but aerodynamic entry, a "blunt front" in laymans' terms. Without relevant data it's hard to be sure, but I wouldn't have thought that the attractive front on the 159 was particularly bad in this respect anyway, airflow doesn't work its way around every nook & cranny before flowing over the rest of the car. What's more important are things like excrescences and panel gaps, something that isn't at all that good on the 159s I've seen, I could get my fingers into gaps around the trailing edge of the rear doors on mine, and that's why the Alfa 4C that set impressive times around the Nürburgring had all the gaps taped over. If you were to fair over the whole front end of one of these cars, as well as uglifying the thing, I doubt if you'd gain more than one or two mph at the top end, which is irrelevant where around-town mpg is concerned, so you wouldn't see any benefit at the pumps.
I'm glad you wrote that, as I was going to clear up the same confusions, but couldn't be bothered, especially with the risk of starting off another argument
As you said, Frontal Area is the cross-section of the entire car - so it's affected by height and width, not the shape of the nose.
Aerodynamics are far more affected by the tail of the car (a long tapering shape being the best), and as you rightfully point out, this has no practical impact below about 60mph anyway, as aerodynamic drag increases as a square of the velocity.
Vehicle weight probably has more to contribute than aerodynamics, but there goes that conversation again
for the record, I'm impressed with my 159's fuel economy when compared against either a FIAT 500 (159 is the same) or an Alfa 166 (159 uses half the fuel)...