These V6 and V8 sedans are the larger and costlier of Infiniti's two premium midsize cars. M35 has a 275-hp V6 and comes in base and Sport models with rear-wheel drive, and as the M35x with all-wheel drive. M45 has a 325-hp V8 and also offers base and Sport models but comes with rear-drive only. All Ms have a 5-speed automatic transmission, ABS, traction/antiskid control, front side airbags, and curtain side airbags. Exclusive to Sports is Infiniti's Four-Wheel Active Steer system, designed to aid handling by automatically steering the rear wheels slightly. Leather upholstery, sunroof, power tilt/telescope steering wheel, and keyless entry/ignition are standard. Sports get aluminum cabin trim, base models wood. Also included are a wireless cell phone link and voice control for some audio and climate functions. Heated/cooled front seats are optional on the base M35, standard otherwise Options on all include audible warning of unintended lane departure, a heated power-reclining rear seat, and navigation system. Also available are DVD entertainment and a rearview camera. Steering-linked xenon headlamps are standard on M45s and M35 Sport.