this is solid works. For aero efficiency i guess you find the Lift/ drag of the car.
When i test; which is really just my little amateur testing. I do the whole car, but i only draw results from say the rear wing, then the front wing, then the body, then the floor; to isolate the parts and see how well they do and what they contribute.
Ofcourse some times i do the whole car and get the L/D or the center of pressure.
I need to get back on this, this weekend. Keep making promises i cant keep with the car. Gonna change it to 2012. Nose will be interesting design.