For coke-bottle styling the car is narrower at the center than at the ends. Preferably both when looked from the top and from the sides
[ame="http://en.wikipedia.org/wiki/Coke_bottle_styling"]Coke bottle styling - Wikipedia, the free encyclopedia[/ame]
As for the most beautiful cars of all time it depends on tastes but a nice compilation can be found here
GRMs Top 100 Most Beautiful Cars: Grassroots Motorsports forum: Grassroots Motorsports Magazine
and here
The 100 most beautiful cars: 100-81 - Telegraph
So maybe coke-bottle styling is so appealing as it relates to living organisms?