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 4 Series Gran Coupe doesn’t offer pre-crash pretensioners.
For enhanced safety, the front seat shoulder belts of the Audi A3 are height-adjustable to accommodate a wide variety of driver and passenger heights. A better fit can prevent injuries and the increased comfort also encourages passengers to buckle up. The BMW 4 Series Gran Coupe doesn’t offer height-adjustable seat belts.
Both the A3 and 4 Series Gran Coupe 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 4 Series Gran Coupe’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.
To provide maximum traction and stability on all roads, All-Wheel Drive is standard on the A3. But it costs extra on the 4 Series Gran Coupe.
Both the A3 and 4 Series Gran Coupe offer rear cross-traffic warning, but the A3 with Rear Cross-Traffic Assist also has Automatic Brake Activation (automatically applies the brakes) to better prevent a collision when backing near traffic. The 4 Series Gran Coupe’s Cross Traffic Warning doesn’t automatically brake.
Both the A3 and the 4 Series Gran Coupe have standard driver and passenger frontal airbags, front side-impact airbags, driver and front passenger knee airbags, side-impact head airbags, front seatbelt pretensioners, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, post-collision automatic braking systems, daytime running lights, lane departure warning systems, rearview cameras, available blind spot warning systems and rear parking sensors.