Front wheel venting
 

From: Automotive Aerodynamics - Sport Compact Car Magazine

Side ducts


Side ducts are primarily seen on race cars for two reasons, because brake and engine cooling is crucial, and because most serious race cars will use a front underbody diffuser that channels airflow toward the rear of the front wheel well. Conventional fender designs trap much of the turbulent air coming off the top and back of the tire generated by the counter rotation of the tires and wheels. Combined with hot air moving through the engine bay and brakes, this generates losses and drag. Side ducting not only provides a smooth outlet for these hot and turbulent gasses, but also turns the flow to exit smoothly along the side of the car instead of directly outward, which would interfere with the turbulent curtain generated by the canards. This reduction of air stagnation inside the bay also helps pull more fresh air through the cooling system. http://image.modified.com/f/15587108...+side_duct.jpg

i wonder how many of these ricers think about how stupid the stick-on ones look, and aren't even functional

Ferrari 599XX

http://4.bp.blogspot.com/_2WGWUztppL...-1920x1440.jpg

BTW for those that did not know this car uses active fans to inject air into the rear wake to reduce drag via the factory taillight locations, thats why they look blacked out, those are actually just black grills, fan assembly is in the trunk, air is sucked in via wheel wells, again also reducing drag.

http://4.bp.blogspot.com/_2WGWUztppL...-1920x1440.jpg

http://www.clutchd.com/wp-content/ga...599xx-live.jpg

So does that make wheel exhausts 'Fast and Furiously Economical" ? ?

Actually exhaust injection is used in many forms of motorsports for drag reduction as well as down force.