The software used to perform the Kyosho Mini-Z Virtual Wind Tunnel simulations was Symscape's Caedium.
From the several different applications I researched while looking for an inexpensive and easy to use solution I chose Caedium for its integration of an intuitive 3D modeling and a powerful set of CFD tools. The 30-day free trial, the extensive set of examples and tutorials, and the direct support from Richard Smith, the mind behind the software, also contributed greatly to this choice.
I started by downloading and installing the software on my Intel i7 Windows 7 (64 bit) machine, and then experimented a lot with the extensive set of examples and tutorials available. It took me a little more than a week to understand and learn how to use the software, and to refresh my knowledge on fluid dynamics. This provided me additional 3 weeks to design my own model and get meaningful results while still enjoying the 30-day free trial.
I found Caedium to be relatively easy to learn and use and a very powerful tool. Keep in mind that I had some knowledge of fluid dynamics (I'm an engineering graduate) but no previous hands-on experience with computational fluid dyanmics (CFD).