It's not only wind tunnel of course, it's also for cooling, which gets to be a serious issue with midengine cars. Then there is downforce which is why the Z07 package has those large spoilers on the back end, and front aero tricks as well. That Vette has the Z07 package on it.
Of course. I was being deliberately simplistic.
Essentially, though, the idea is that they're all solving for the same issues.
First is that you need two human-sized seats, one of which has access to the vehicle controls. There are only so many places you can put the driver and so many shapes you can ask them to conform to without being TOO uncomfortable.
Second is performance, which pushes you into mid-engine designs for weight distribution and traction. Which also involves downforce, and reducing drag coefficient as much as you can EXCEPT as it relates to downforce production.
Third are the effects of that performance, which is the need to cool your engine and brakes, which is why you're going to have air intakes in the same places on all cars of similar design and capabilities.
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But where I came from was once hearing my dad complain about all the cars looking the same. Of course they look the same. Vehicles of a certain class, i.e. mid-sized CUVs for example, are all trying to accomplish the same thing regarding occupant seating and comfort, cargo capacity, aerodynamics/fuel efficiency. Since they're all designed to meet the same constraints, it's simple to understand why they all end up with the same solution, and all you have to distinguish is little styling cues. So I came up with the (short and oversimplified) saying of they're all the same because they're all designed by the same computer programs and optimized for the same wind tunnel.
In past eras, when we didn't understand aerodynamics, and gas was cheap, you had a lot more design freedom.