Just as we're settling in to resume the ride, Pfeifer announces we're going to do it again--except now he has dropped well behind the vehicle ahead of us and tips his right foot much closer to the floor. We're approaching 100 mph when he repeats a maneuver that might send an ordinary SUV somersaulting into the bush. The Cayenne responds like a jet fighter in dogfight mode.

Maybe this is a real Porsche, even if it has its engine in front, seats for five, and room for cargo.

Back in our lane, and back to normal speed (but long before the back-seat passenger's heart rate has returned to normal), Pfeifer smiles and chassis engineer Eugen Oberkamm confirms "the PSM works," before he returns to the notes he's been making all along. One note says to check the seal at the front edge of the sunroof; Oberkamm heard air leak as Pfeifer tried to rip the chassis from its wheels.

Cultural commentator Bill Bryson describes Australia as the "driest, flattest, hottest, most desiccated, infertile, and climatically aggressive of all the inhabited continents." He provides a list of the snakes, spiders, ticks, crocodiles, sharks, and even caterpillars that can end your life. "In short," Bryson says, "you don't want to be caught in the Outback."

As we're about to discover. We're some 850 miles into our drive when we stop at the Kulgera roadhouse. In the flat but dangerous Outback sea, a roadhouse is a lighthouse, a place of refuge and relief: fuel station, emergency repair shop, snack bar, tavern, campground, and motel, all rolled into one and all sort of rolled back into the '50s.

Travelers stop at every roadhouse. Nobody wants to run out of fuel in the Outback.

The roadhouse also provides a shady break. We'd call it a cool, shady break, but the thermometer on the covered patio points to triple digits.