A car inside JRollon Airplanes? Well, this one is more near as a plane than as a car. The hability of the Bloodhound SSC is to not fly! 
I suppose that someone from the Bloodhound project came to Austin and offered a money to make testings with xplane, or other projects that may have Austin internally to play with. What I know is that it was fun to sit a little appart from wings for a moment.