STAC uses computer generated simulations, based on years of data taken from the University of Waterloo wind tunnel. A 3D scan is taken, then run through software developed by several UW Engineering grad students and the UW Fluid Mechanics Research Lab. I inquired about an actual wind tunnel session, but these sessions are far out of my budget. STAC was very reasonable and at least gives us an idea of where to focus. In their conclusion, STAC felt that flow separation dominates our total drag, so reducing area will reduce drag. Cleaning up airflow behind may effect cD, but will not reduce area. So, we should see more gains by focussing on reducing frontal area than we would trying to clean up unsettled air behind the rider (me).