Both the CT4 and Legacy have child safety locks to prevent children from opening the rear doors. The CT4 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 Legacy’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 Cadillac CT4 has standard driver and front passenger side knee airbags mounted low on the dashboard. These airbags helps prevent the driver and front passenger from sliding under their seatbelts or the main frontal airbags; this keeps them better positioned during a collision for maximum protection. Knee airbags also help keep the legs from striking the dashboard, preventing knee and leg injuries in the case of a serious frontal collision. The Legacy doesn’t offer a front passenger side knee airbag.
The CT4 Premium Luxury/Sport offers an optional HD Surround Vision to allow the driver to see objects all around the vehicle on a screen. The Legacy only offers a rear monitor and rear parking sensors that beep or flash a light. That doesn’t help with obstacles to the front or sides.
The CT4 has a standard blind spot warning system which 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 Legacy’s blind spot costs extra.
To help make backing out of a parking space safer, the CT4 has a standard rear cross-path warning system, which uses sensors in the rear bumper to alert the driver to vehicles approaching from the side, helping the driver avoid collisions. Rear cross-path warning costs extra on the Legacy and isn't available on the not available.
Compared to metal, the CT4’s plastic fuel tank can withstand harder, more intrusive impacts without leaking; this decreases the possibility of fire. The Subaru Legacy has a metal gas tank.
Both the CT4 and the Legacy have standard driver and passenger frontal airbags, front side-impact airbags, driver knee airbags, side-impact head airbags, front seatbelt pretensioners, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, daytime running lights, lane departure warning systems, rearview cameras and available all wheel drive.