Again and again and again
The earliest car that focused on fuel efficiency was(IIRC) the Dymaxion. It was a long teardrop with the steering on the back wheel(seriously, WTF!?). The only prototype was destroyed when the driver turned the wheel wrong, forgetting to turn it the opposite of the way he wanted to go. Since this was ~WWII, it was the only attempt for a few decades. Enter the Information Age. All cars are designed like crap and the fuel efficient ones are twice as bad, not to mention worthless in a crash. If you ask me, the best way to approach the issue is to take an already heavy vehicle(like a pickup), beef up its suspension and shove batteries where the gas tank and motor used to be(the reasoning behind this is that you can fit more batteries in the larger vehicles, especially if you put some where the big toolbox goes in the bed).
Of course, I'll always prefer the car that can total every other car on the road and drive away like nothing happened(paint job can take as much damage as it wants; I don't care).