[ETriggs]

IMHO, I think they've all tried to find the perfect aerodynamic design in order to improve gas mileage. Once you find the perfect shape, the only thing you can change are the headlights and taillights. 50s designs were out to dazzle the public. Today we have ho hum.

This. There are three areas auto manufacturers can improve efficiency in cars/trucks.
1. Aero / drag
2. Powerplant
3. Structural mass

That's why F-150's and other vehicles are now made out of aluminum. If its shaped like a brick, it better be lightweight.