The air resistance is strongly influenced by the basic form of a vehicle. An optimization of the cw value can be achieved by improvements in detailing. These extend over the modification of details as, for example:
  Optimization of curvatures and radii of edges.
 •Pulling-in.
 •Position and dimension of spoilers.
 •Smoothing of the under body by covering components and tail diffuser.
  Optimization of the airflow around the wheel.
These measures have a large influence on aerodynamics, but do not affect the design that was previously determined.