The A3’s pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The Impreza doesn’t offer pre-crash pretensioners.
Both the A3 and Impreza have child safety locks to prevent children from opening the rear doors. The A3 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 Impreza’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 Audi A3 has standard driver and front passenger side knee airbags mounted low on the dashboard. These airbags help 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 Impreza doesn’t offer a front passenger side knee airbag.
The A3 has a standard Secondary Collision Brake Assist, which automatically applies the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The Impreza 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 A3 has standard backup collision prevention system that uses rear sensors to monitor for objects to the rear and automatically applies the brakes to prevent a collision. The Impreza doesn’t offer backup collision prevention brakes.
The A3 Premium Plus has a standard Top View Camera System to allow the driver to see objects all around the vehicle on a screen. The Impreza only offers a rear monitor.
The A3 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 Impreza’s blind spot costs extra.
To help make backing out of a parking space safer, the A3 has standard Rear Cross-Traffic Assist and Automatic Brake Activation automatically engages the brakes to help avoid a collision. Subaru charges extra for Rear Cross Traffic Alert on the Impreza and the Impreza’s Rear Cross Traffic Alert does not include automatic braking.
Both the A3 and the Impreza have standard driver and passenger frontal airbags, front and rear side-impact airbags, driver knee airbags, side-impact head airbags, front seatbelt pretensioners, 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 and rearview cameras.