The Toyota Prius is a full series-parallel hybrid electric compact car developed and manufactured by the Toyota Motor Corporation. The second generation Prius had been completely redesigned as a compact fastback. The XW20 series represented the second generation of the Toyota Prius, replacing its XW10 predecessor. The United States Environmental Protection Agency (EPA) and California Air Resources Board (CARB) rated the Prius as among the cleanest vehicles sold in the United States based on smog forming and toxic emissions in 2008. Toyota sold about 1,192,000 units of the second generation Prius worldwide.