Stephan Wilkinson takes an up-tempo tour of operatic proportions at the wheel of an Audi A4 Cabriolet

The route from Mozart's Salzburg to Wagner's Bayreuth is a storybook spectacle of the snowcapped mountains, moody forests, and hilltop castles of Bavaria. Just north of this familiar scenery lies Thuringia, concealed for decades behind the Iron Curtain. Now open for business, Thuringia is the wine to Bavaria's beer, as different from the south as Tristan is from Figaro.

With the top down on our Teutonic mount, my right-seater and I set off from Salzburg on a summer day. The new Audi A4 Cabriolet is a solid, elegant four-seat convertible—a rare breed—with a remarkably engineered transmission that may be the best automatic on the planet (see 'Behind the Wheel,' below).

Day 1: Salzburg to Regensburg, 137 miles
Mozart left his native Salzburg for the more swinging Vienna, but his name and music are imprinted everywhere on the city of his birth. With strains of The Magic Flute running through our heads after last night's broadly comedic production at the Festspielhaus, we set off on the two-lane B20 toward Regensburg.

Right away, the Audi's GPS is trying to convince me to take the autobahn. That route, albeit far longer, is probably faster—but who cares? We want country roads and character, not a superslab. This distinction is clearly beyond the ken of Bitchin' Betty, the industry's nickname for the plummy-voiced GPS that will lead the way—if you let her. It will be days before I make peace with this silicon wonder, whose voice commands I find far more infuriating than helpful. Is this $2,100 option 700 times better than a $3 road map? Maybe in European cities, where streets were laid down during the Middle Ages, but I question its value in rectilinear America.

Bavaria is life-sized Lionel, God's own model-train layout, including here and there brightly painted choo-choos straight out of a tin-toy catalog. The fields are evenly cropped, the little lawns neatly mowed, and blooming window boxes are set in orderly rows before gleaming panes of glass. If anyone dared to park his Opel in the front yard with a FOR SALE sign in the window, the Bavarian Beauty Police would be on the scene in minutes.

'You Americans have no architecture,' a Bavarian backpacker I picked up on a California highway once griped to me. I see now that I should have replied, 'You Bavarians have architecture, but it's all the same.' The architects here have an obsession with beige stucco, which after a while is anesthetizing.

It's Sunday and the traffic is light. A line of motorcyclists in Valkyrie-sleek black leathers and helmets rumble past us, but even these apparent renegades are driving conservatively. Germans drive at wonderfully obscene clips on the sections of autobahn that are ungoverned by speed limits, but elsewhere they obey posted limits to the letter. We do pass one radar trap—an unmarked Audi wagon parked in a pull-off with an odd antenna shooting through the back window. I spot it only because a selfless, arm-waving Bavarian has devoted his Sunday afternoon to standing on a highway overpass, signaling to slow down.