Both the Defender 110/130 and Cayenne have child safety locks to prevent children from opening the rear doors. The Defender has power child safety locks, allowing the driver to activate and deactivate them from the driver's seat and to know when they're engaged. The Cayenne’s child locks have to be individually engaged at each rear door with a manual switch. The driver can’t know the status of the locks without opening the doors and checking them.
The Defender’s standard lane departure warning system alerts a temporarily inattentive driver when the vehicle begins to leave its lane and gently nudges the vehicle back towards its lane. A lane departure warning system costs extra on the Cayenne.
The Defender has a standard blind spot warning system that uses sensors to alert the driver to objects in the vehicle’s blind spots where the side view mirrors don’t reveal them and moves the vehicle back into its lane. A system to reveal vehicles in the Cayenne’s blind spot costs extra.
To help make backing out of a parking space safer, the Defender’s standard Rear Traffic Monitor uses sensors in the rear to alert the driver to vehicles approaching from the side and Rear Traffic Braking automatically engages the brakes to help avoid a collision. The Cayenne doesn’t offer a rear cross-path warning system.
The Defender’s driver alert monitor detects an inattentive driver then sounds a warning and suggests a break. According to the NHTSA, drivers who fall asleep cause about 100,000 crashes and 1500 deaths a year. The Cayenne doesn’t offer a driver alert monitor.
Both the Defender and the Cayenne have standard driver and passenger frontal airbags, front side-impact airbags, side-impact head airbags, four-wheel antilock brakes, all wheel drive, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, daytime running lights and rearview cameras.