Before Detroit came to dominate the industry, Indianapolis, a 2.5-hour drive south of South Bend, was an early center of American automobile manufacturing, home to such classy marques as Stutz, Marmon, and Duesenberg, and of course the Indianapolis 500, perhaps the most famous car race in the world. Held the Sunday before Memorial Day almost every year since 1911, the Indianapolis 500 is still the biggest thing in town, drawing upward of a half million spectators to “The Brickyard,” the oldest racetrack in the country. The rest of the year, the speedway is open for tours ($30), on a bus that cruises around the legendary 2.5-mile oval. Tours leave from the excellent Indianapolis Motor Speedway Hall of Fame Museum (4790 W. 16th St., 317/492-6784, daily, $10), which displays some 75 racing cars, from the Marmon “Wasp,” which won the inaugural Indy 500 race, to the latest Indy champions. The museum is located on the speedway grounds at in the city of Speedway (pop. 12,102), an enclave in the northwest quarter of Indianapolis’s pancake-flat sprawl.