What car does not have "similarities" to other cars?
"Look, Dude! It's got four wheels ... they stole that!"

There's a difference between just "similarities" & necessities. All automobiles need wheels, doors ( of some sort ), an engine, again of some sort/variety, etc, making these things "necessities". Similarities are a different kettle of fish. Have you ever seen a Ferrari look vaguely "similar" to a Mustang? Or a Lamborghini look "similar" to a Dodge Challenger? Once you understand the difference between the 2, similarities & necessities, your argument that all cars are " similar" is quite incorrect.
It's about design, creativity, indivualism of brands etc.... & not wanting to "look" like every other car, or a particular car, out there today. In this instance GM's new 2014 Corvette doesn't appear to have ANY individualism/creativity etc... It simply looks like a parts pack, working man's Ferrari Berlinetta cross Viper cross GTR35....