One more I forgot to add is the underside of a ( used ) Mazda 6.
I was surprised to see that almost every new car and truck/SUV that i looked at had the same amount of aerodynamic work as those from twenty years ago. Nothing seems to have improved !
I did happen to be looking at mid nineties Audi / VW ( Passat ? ) at a used car dealership once ( nope - no camera
) and was very impressed by the level of detail under the car. The front engine pan had NACA ducting ( One of the members here actually modified one to fit his van ) and what blew my mind was that the center section of the car had small panels which had dimples ( yes -
dimples ) approx. 1" in diameter. This puzzled me since dimples aren't supposed to really do anything - but why would they go through all the trouble of having the dimpled panels if no one even knew they were there ? I seem to remember a member here from Europe posting a similar dimpled panel on a VW.