At the entrance to the Fort Hunter Liggett military reservation, we're stopped by the post police for a license-and-registration check. "That's a problem, Officer," I grovel. "This car isn't really registered. It's a prototype that we're testing, running with manufacturer plates. Strictly speaking, it's illegal. In fact, it's going to the crusher in several months when its permit runs out."

Hmmmm. The cop goes off to consult in the guardhouse and comes back.

"Unfortunately, we're going to have to confiscate your car," he says grimly. "So that we can test it ourselves," he says with a laugh. "Go on, get outta here. Just watch out for the wild pigs and Humvees."

The road through the military reservation would sure be the place to do the testing. It twists and winds through the Los Padres National Forest, as extreme a sports car challenge as I've ever seen. Yes, I've driven the notorious Tail of the Dragon—U.S. 129 in Tennessee—which supposedly has 318 curves in less than 12 miles, but the Dragon is so slow and convoluted that it's more a curiosity than a challenge. This road, however, is a fabulous series of fast corners and constantly changing forestation and elevation. Brook doesn't have the wheel straight for a second. ("Shut up, Dad, I know what I'm doing. . . .")

The Pacific comes into view suddenly and immensely, from a considerable height as we corkscrew down the steep western slopes of the Santa Lucia Range. No European corniche can compete with such wild splendor. It leads us to what some generally call the Pacific Coast Highway—the PCH, in Southern Cali shorthand—but is really California Highway 1, sometimes U.S. 101. Just keep the water on your left and in sight and you'll be on one of the world's iconic roads all the way to northern Oregon.

"The One" takes us to classic Big Sur, where I pay my all-time domestic record for gas—$5.16 a gallon for 91-octane—and then wheel up to the entrance of the finest lodging in the area, the Post Ranch Inn.

And whom should I meet but the only adult who in four days has recognized the GT-R for what it is: the most important, highest-performance Japanese supercar ever to be brought to the United States. He's a guest at Post Ranch, an ex–race car driver, and it turns out that he and his wife live not 30 miles from us back in upstate New York.

"Good Lord," he says. "I just ordered one of those, but this is the first time I've seen it." I throw him the keys, tell him the gas tank is full and to drive it like he stole it. Fortunately, he does bring it back.