The Vortex is a three wheeled car which is built from plans. That's right; there is no kit, just plans.
Here's a great photo of the late Arvil "Shep" Shepherd's Scorpion (A highly-modified Vortex) and Dan Lenox's Vortex. These are two of the three known Vortex cars which have been completed from the plans.
Here's a link to Dan's FANTASTIC Vortex build-blog, which documents every step of the build process.Here's a link to Shep's Scorpion Build Pages. This will likely be taken down soon, so check it out while you can.
Here's a link to the Vortex Three Wheeled Car Plans.