It's California wine country, and we're nearly upside down. Half a mile high, pilot Kenny Price has rolled our glider into a fast dive, and suddenly the fertile soil is threatening to smash us like grapes. But quicker than I can scream, "Eject!" Price pulls back on the stick, and I'm squeezed into my seat by 2.5 G's. Just as my eyes start to roll back into my head, the force melts away and the world outside the canopy bobs upright again. "That's called a wingover," Price says casually from the backseat. Good thing I saved the wine for after the flight.

It's hard to think of a more well-rounded weekend road trip than a drive through the fecund vineyards of Napa Valley. Between San Francisco and the town of Napa traffic can be rough, but your consolation is a golden, rolling landscape; organic, locally grown food; and wine that puts the French to shame. North of Napa, the well-maintained, traffic-free, twisted two-lane highways, particularly Highway 128, are ideal for pure driving fun. And there are plenty of opportunities for adventure: cycling back roads between vineyards, paddling the Napa River, and to the north, hiking, biking, and camping in Mendocino National Forest. The area around Napa is also perfect for gliding -- riding thermal currents and wind gusts in a featherweight, engineless plane.

So on a sunny fall Friday, I had crossed the Golden Gate Bridge out of San Francisco and headed north in my weekend ride, a 2006 Audi A3 hatchback. The warm Marin County air tugged at my sunglasses as the city faded away. I turned north onto Highway 121 at Sears Point, home to Infineon Raceway, the sensational race track where years ago I did some of my earliest laps in an open-wheeled race car; a half hour later, I reached Napa.

I would have stopped to raise some spirits, but I was due in the tiny hamlet of Williams, northeast of Napa Valley, where the next day I had an appointment with Kenny Price and his glider. For the next two hours, on nearly traffic-free asphalt that hacks through scrubby hills and dense woods, I gunned the A3 hard. Almost too soon, I arrived in Williams, grabbed a four-cheese pizza and a beer at the lodge-like Granzella's Restaurant, and retired to my room in the adjoining hotel. The next morning dawned cool and clear. Just outside town, Williams Soaring Center looked more like a farm than an airport: a narrow 2,500-foot runway tucked in amid cultivated fields, with an unadorned hangar full of picnic tables for a pilot's lounge.

Price and I rolled a German-built Schleicher K-21 glider out from under a metal awning; once we belted in, another pilot in a Piper Pawnee prop plane lined up to tow us aloft. After a quick, bumpy sprint down the runway, we floated into the air. At 4,000 feet Price pulled a knob and the tow rope disconnected. We were flying on our own.

Which brings us back to those acrobatics: Even as we're barreling toward the ground, the only sound is a peaceful rustle of wind. The cockpit fits like a wet suit, and the canopy wraps around you like a fighter jet's. In calmer moments, I take in the view: To the east I can see the Sutter Buttes; to the west, the Coast Ranges and the northern tip of Napa Valley. "Sometimes when I'm doing this," Price says, "I'll look over and see a bald eagle flying off my wingtip."

After we touch down, a celebration is in order -- so, naturally, I head back toward Napa. I aim west along Highway 20, savoring the fresh air, the warm sun, the lightly traveled road. I stop for an apple and a Coke at a little red shack of a fruit stand, then turn south at California's second-largest body of freshwater, Clear Lake, where you can find some of the best bass fishing in the state. Less than 90 minutes later, I'm cruising down Highway 29, Napa's wine-filled main artery, which rolls past endless vineyards and well-manicured estates. I pass Charles Krug, Beringer, Louis M. Martini, and more, but it's Grgich Hills, whose vintner made the 1973 chardonnay that famously beat the French in a 1976 competition, that draws me in.

The foyer, with wine barrels piled high nearby, buzzes with conversation and clinking glasses. I sample the vineyard's latest chardonnay and follow it with a dessert wine called "Violetta." As I finish my drink I can feel it going to my head, and my wine-country weekend comes to a smooth, sweet, lingering finish.