Want to see a truck put together in about 60 seconds in the same place that once produced Model As? A tour of the Ford Rouge Factory is a must for any car fanatic -- or history buff --visiting the Motor City. Purchase tickets at Henry Ford Museum and hop a bus to the sprawling factory for a self-guided tour. This is a clean, modern, visitor-friendly operation with two theaters showing films about the factory's historic significance and explaining how modern vehicles are built. Overhead walkways allow visitors to watch the plant assemble Ford F-150 trucks using "smart tools" that build upon Ford's original assembly-line concept. Also noteworthy are green amenities the Rouge facility has introduced. Most impressive is the world's largest "living roof," which uses groundcover planted on the roof to filter rainwater and help insulate the building.