The 350 and 450h both carry a 3.5L V6 under the hood. The 350 is rated at 275 horsepower, while the 450h can do a combined 295 horsepower, thanks to the assistance of the hybrid powertrain's electric motor. The 350 uses a conventional 6-speed transmission, but the 450h comes with a continuously variable transmission. The 450h hybrid system includes a 288-volt battery pack that sits under the rear seat, sending power to the front mounted motor-generator that drives the front wheels. In all-wheel drive trims, a second motor-generator drives the rear wheels. Both models also carry an engine-driven generator to functions as a starter and a charger for the battery pack. Lexus boasts a handling system called Vehicle Dynamics Integrated Management (VDIM); it's standard on the 450h and optional on the 350. If the system detects a loss of control, it uses an array of electronic systems ? anti-lock brakes, brake assist, traction control, stability control and throttle control to help the RX get back on track. Further safety options include adaptive headlights and a pre-collision system with Dynamic Radar Cruise Control to set the RX's speed in relation to the car ahead. The RX has 10 standard airbags, a rollover sensor to inflate side curtain airbags and active front headrests. Inside, the RX features push-button start, 10-way power seats with memory, steering-wheel mounted controls, Bluetooth connectivity, and the Lexus Premium Audio system. Options include a smog detector, leather seats, rear-seat entertainment system, 15-speaker Mark Levinson surround-sound system, navigation system and back-up camera.