Thanks @lafars these wind tunnel air flow pics are very interesting. The car makers especially with sports cars have to find the fine line between downforce and low drag coefficient. With the active aerodynamics they can achieve low drag in a straight line and high downforce in corners.
I wish more manufacturers would release CdxA data; it's a very useful thing to know when comparing vehicles. Furthermore, measurements can vary tremendously depending on the method used (wind tunnel vs. coast-down testing) and conditions.