Some aero touches on Commodores.
The VN Commodores squared off rear wheel arch and the flat pizza pan style hub caps reduce drag.
The VP Calais rear wheel arch spats goes one step further reducing the wheel opening and in turn reducing drag.
Reducing the upper grill opening reduces drag as it promotes more air up and over the smooth bonnet than through the radiator (high drag)
VN Group A SS
VL Group A SS Walkinshaw
Even the standard VP upper grill is pretty aerodynamic