Honda surprised the crowd at Chicago with a Civic Si sedan concept, which previews a production model that Honda will add to its lineup late this fall. The sedan uses the same powertrain as the Si coupe: a high-revving, 197-hp, VTEC four; a six-speed manual gearbox; and a limited slip differential. Honda was not forthcoming with further details about the production car, but the concept also has eighteen-inch wheels, a lowered suspension, Brembo brakes, and a rear wing. Honda has offered Si versions of the Civic going all the way back to 1986, but this will be the first-ever four-door Si.