The Cayenne Coupe has a standard Multi-collision Brake System, which automatically applies the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The RDX doesn’t offer a post collision braking system: in the event of a collision that triggers the airbags, more collisions are possible without the protection of airbags that may have already deployed.
Over 200 people are killed each year when backed over by motor vehicles. The Cayenne Coupe offers optional Maneuver Assist that uses rear sensors to monitor for objects to the rear and automatically applies the brakes to prevent a collision. The RDX doesn’t offer backup collision prevention brakes.
A passive infrared night vision system optional on the Cayenne Coupe helps the driver to more easily detect people, animals or other objects in front of the vehicle at night. Using an infrared camera to detect heat, the system then displays the image on a monitor in the dashboard. The RDX doesn’t offer a night vision system.
Both the Cayenne Coupe and RDX have rear cross-traffic warning, but the Cayenne Coupe has Rear Cross Traffic Alert (automatically applies the brakes) to better prevent a collision when backing near traffic. The RDX’s Rear Cross Traffic Monitor doesn’t automatically brake.
Both the Cayenne Coupe and the RDX have standard driver and passenger frontal airbags, front side-impact airbags, driver and front passenger knee airbags, side-impact head airbags, height adjustable front shoulder belts, four-wheel antilock brakes, all wheel drive, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, daytime running lights, lane departure warning systems, blind spot warning systems, rearview cameras, rear cross-path warning and available around view monitors.
The Porsche Cayenne Coupe weighs 682 to 1705 pounds more than the Acura RDX. The NHTSA advises that heavier vehicles are much safer in collisions than their significantly lighter counterparts.

