For enhanced safety, the front and rear seat shoulder belts of the Mercedes A-Class have pretensioners to tighten the seatbelts and eliminate dangerous slack in the event of a collision and force limiters to limit the pressure the belts will exert on the passengers. The BMW 4 Series Gran Coupe doesn’t offer pretensioners for the rear seat belts.
The A-Class offers an optional Surround View System to allow the driver to see objects all around the vehicle on a screen. The 4 Series Gran Coupe only offers a rear monitor and front and rear parking sensors that beep or flash a light. That doesn’t help with obstacles to the sides.
Both the A-Class 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, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, daytime running lights, blind spot warning systems, rearview cameras, driver alert monitors, available all wheel drive and lane departure warning systems.

