The C350 Sport sedan and C350 Luxury sedan are both powered by a 3.5-liter V6 generating 268 horsepower. The Sport gets the six-speed manual and larger performance tires; the Luxury version gets the seven-speed automatic and all-season tires. Both add position memory for the seats and mirrors. All-wheel drive, which Mercedes calls 4MATIC, is available on the C350 Luxury sedan; 4MATIC comes packaged with heated front seats. It also has side-impact airbags for front passengers as well as curtain-style head-protection airbags for front and rear passengers.For 2007, the Mercedes-Benz C350 discontinues the C55 AMG and receives active head restraints.