[RedDevil]

I wondered at the scooplike ridges at the side of the bumpers of many modern cars. As if they were designed to create drag.
I believe they do, and that it is a good thing.
Because if the sides were smooth the air would flow swiftly over it at an angle.
It would not be able to make a smooth transition to the side and become turbulent.

Now those scoops and ridges effectively slow the air down (relative to the car!), so they create a high(er) pressure. This affects the general air flow to move over rather than along the sides of the car.
Apparently, that works out better. The line over the roof approaches the template on many cars. The sides are more or less straight and have ridges, wheels, mirrors, etc.

Another example can be seen in the prototype of the new Honda Fit.

Notice the A pillars. They protrude ahead of the windscreen, and their base continues over the hood. Why? To force air over rather than along the car.
It has the bumper scoops on the sides too, as almost all new cars do.