Toyota Motor Sales, U.S.A. (TMS) is the US sales, distribution, and marketing unit for Toyota Motor's Toyota, Lexus, and Scion brands. A majority of Toyotas sold in the US are also made in the US. Those models include the Avalon, Camry (the US's top-selling vehicle), Highlander, Sequoia, Sienna, Tacoma, Tundra, and Venza. TMS is in charge of sales, marketing, and service of its cars, light trucks, hybrids, and SUVs in 49 states. Sales are conducted through about 1,500 dealerships throughout the US. The company's TRD (Toyota Racing Development) U.S.A. division designs and assembles engines and develops chassis and other technology for Toyota-sponsored race cars.