The "truck" was built and driven by New Zealander Rod Millen (Rhys's dad) for the 1998 Pikes Peak Hillclimb. The vehicle has nothing in common with the Tacoma and is, in fact, built on a chrome-molly tubular space frame chassis covered in a carbon fiber body. Power is generated by a 2.1-liter, four-cylinder, turbocharged and intercooled engine pumping out something in the neighborhood of 1,000 HP. It can hit 125 MPH in 4.9 seconds. With this "truck" Millen won the Pikes Peak Unlimited class in both 1998 and 1999.
This video shows Millen driving the vehicle at the 2007 Goodwood Festival of speed, a non-competitive rolling showcase of rare racecars, not a full-on hillclimb. Keep that in mind as Millen tries furiously to keep the damn thing on the track, which he manages, we're guessing, for 75% of the climb. God, what a bastard of an automobile.