I would love to see some collaboration to conduct CFD analysis of ecomodded cars, thus definitively answering questions about how many MPG rear wheel skirts would give, and comparing the relative effectiveness of several proposed grille block designs, for example.
This collaboration does not require money. As you said, if we create a model, it is our property, and we could share it here under a Creative Commons license. OpenFOAM is Free, so no money there. For CAD software, any software that can handle .DXF (drawing exchange format) is fine. If you're rich, buy a copy of a professional CAD suite. If you're a student or an engineer, use your employer's/school's copy. If none of these apply to you, get free CAD, such as this one that was on the first page of Google:
GSI: CAD X11 Features