The XM’s pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The RX doesn’t offer pre-crash pretensioners.
To provide maximum traction and stability on all roads, All-Wheel Drive is standard on the XM. But it costs extra on the RX.
To help make backing out of a parking space safer, the XM has standard Cross Traffic Warning with braking function with automatic braking, systems which detect vehicles approaching from the sides and can automatically apply the brakes to prevent a collision. Parking Support Brake costs extra on the RX.
Both the XM and the RX have standard driver and passenger frontal airbags, front side-impact airbags, driver and front passenger knee airbags, side-impact head airbags, front seatbelt pretensioners, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, post-collision automatic braking systems, daytime running lights, lane departure warning systems, blind spot warning systems, rearview cameras, rear cross-path warning and driver alert monitors.
The BMW XM weighs 1313 to 1908 pounds more than the Lexus RX. The NHTSA advises that heavier vehicles are much safer in collisions than their significantly lighter counterparts.

