The Z has standard Active Head Restraints, which use a specially designed headrest to protect the driver and front passenger from whiplash. During a rear-end collision, the Active Head Restraints system moves the headrests forward to prevent neck and spine injuries. The 911 doesn’t offer a whiplash protection system.
The Z 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. A system to reveal vehicles in the 911’s blind spot costs extra.
To help make backing out of a parking space safer, the Z has standard Rear Cross Traffic Alert, helping the driver avoid collisions. Porsche charges extra for Rear Cross Traffic Alert on the 911.
Both the Z and the 911 have standard driver and passenger frontal airbags, front side-impact airbags, side-impact head airbags, front seatbelt pretensioners, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, daytime running lights, lane departure warning systems, rearview cameras and driver alert monitors.

