Toyota's first minivan experiment was the Previa which had a wildly unorthodox mid-engine rear wheel drive design. They replaced that model with the much more conventional Camry-based Sienna in 1997. Now a front engine, front wheel drive V6, the Toyota Sienna parts have been much more successful and have risen to the top of the minivan class. It was one the first minivans to incorporate duel sliding doors instead of just one on the passenger side. The van is named after the city in Italy. The current third generation model is the only minivan on the market to offer all-wheel drive. With GM and Ford out of the minivan market, the Toyota Sienna's only major competitors are the Chrysler Town & Country and the Honda Odyssey.