At the track driving events we attend, the topic of drag and aerodynamics — how effective is that wing on the back of the car — often comes up. Our car is street legal, so there’s only so much lowering we can do. We do have a fairly modest wing and a splitter on the front to try to keep air from under the car and forcing it up.
So I enjoyed finding Mike Turner’s DIY Aero Civic project, where he’s used common-place materials from the local hardware store to lower his ‘92 Honda Civic’s drag coefficient and improve its gas mileage. That’s the result in the top picture. He’s based his design on German experiments with low coefficient of drag automobiles in the 1930’s (that’s one of the German cars, a 1939 Maybach Stromlinienkarosserie, in the second photo).