Crash safety structures are designed into the frame channels well beneath the skin of the vehicle.
Small cars are the most affected by crashes, have the poorest safety ratings. I am sure that there are a tonne of constraints as to the range of possible designs, when it comes to a small car with an excellent safety rating.
Camaro, Challenger, and Mustang, all have retro styled bodies, which are distinctly not aerodynamic in appearance. Most of the grille surfaces of these vehicles look like giant parachutes formed into the front.
Grill surfaces are irrelevant in shape, if they're a grill then air flows through them anyway?
According to wiki
, a fair improvement in aerodynamics has been made from the old mustang to the new... The 70s mustang had a CD of .44 or .46 (coupe or fastback), where as the 1999 model has a CD of .36.
Quite a difference, given the similar body styles. Even though it's still not an overly impressive figure that they've ended up with, I guess.
I'd wager it's not by chance that it's improved that much however.
As it also states in the wiki:
The drag coefficient is a common metric in automotive design, where designers strive to achieve a low coefficient. Minimizing drag is done to improve fuel efficiency at highway speeds, where aerodynamic effects represent a substantial fraction of the energy needed to keep the car moving. Indeed, aerodynamic drag increases as the square of speed. Aerodynamics are also of increasing concern to truck designers, where a lower drag coefficient translates directly into lower fuel costs.
About 60% of the power required to cruise at highway speeds is taken up overcoming air drag, and this increases very quickly at high speed. Therefore, a vehicle with substantially better aerodynamics will be much more fuel efficient.
A 20% improvement on 60% of the gas consumption at highway speeds is worth doing something about for the manufacturers.
A Toyota prius has a stupidly good CD of .25, for this reason.
Looking at the list on the wiki page, there's a general correlation between a lower CD for all types of vehicles, and how new they are.
As I've said, even if someone wanted to make a distinctive old car like an Anglia or a Hillman Imp anymore, they couldnt feasibly do it.
Several cars have gone to forward swept noses, most notably the Lancer, all of the Tentacle Manga restyled Mazdas (Mazda3, Miata, etc.)
and the Toyota/Subaru coupe that, as of this week, is still planned for production. Forward swept surfaces are not aerodynamic.
A 2010 Mazda 3 has a rather impressive CD of .29, not bad if they're not bothering trying to be aerodynamic at all.
Fuel efficiency is clearly not a factor because cars have not been getting more fuel efficient. (What's the fuel economy of a 1970's import vs. today's offerings? Why does my 1989 box get better fuel economy than anything that Ford, Chrysler, or GM is selling?)
Because modern cars arent allowed to just be tin cans anymore.
They have to have airbags, crash structures, side intrusion, blah blah.
There's no doubt in my mind that a modern economy oriented small car will be significantly more fuel efficient than nearly anything from the 80s or early 90s.
(Which is not to say that it's more cost effective over the long run, given the massive increase in purchase price of the car)
Given those examples, the only thing driving the appearance of cars is the styling that the car makers (specifically the people approving and disapproving the designs) think that the public will buy. It's pretty clear that the public do not want small, light weight cars with good handling and enough power to make them fun to drive.
Sadly I agree, this pretty much seems to be the case.