Actually aerodynamic drag becomes dominate at a lot lower speed than, that from memory around 30 kph it is something like 80% of the resistance to forward movement on a "normal" bike.
Have a play with this calculator if you want to get a feel for the difference a fairing/windscreen can have. http://www.kreuzotter.de/english/espeed.htm

If they tested the bike without a rider in the article referenced, it would have been totally pointless. Anyone confirm the test configuration?