The BMW 2 Series 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 BRZ doesn’t offer a front passenger side knee airbag.
The 2 Series has a standard PostCrash iBrake, which automatically applies the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The BRZ 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.
The 2 Series offers all-wheel drive to maximize traction under poor conditions, especially in ice and snow. The BRZ doesn’t offer all-wheel drive.
The 2 Series offers an optional Surround View to allow the driver to see objects all around the vehicle on a screen. The BRZ 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 2 Series 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 and moves the vehicle back into its lane. Only the BRZ Limited offers a blind spot warning system.
To help make backing out of a parking space safer, the 2 Series 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. Only the BRZ Limited has a rear cross-path warning system.
Both the 2 Series and the BRZ 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, daytime running lights and rearview cameras.
The BMW 2 Series weighs 638 to 1056 pounds more than the Subaru BRZ. The NHTSA advises that heavier cars are much safer in collisions than their significantly lighter counterparts. Crosswinds also affect lighter cars more.