The 7 Series’ pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The 300 doesn’t offer pre-crash pretensioners.
Both the 7 Series and 300 have child safety locks to prevent children from opening the rear doors. The 7 Series 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 300’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.
In the past twenty years hundreds of infants and young children have died after being left in vehicles, usually by accident. When turning the vehicle off, drivers of the 7 Series are reminded to check the back seat if they opened the rear door before starting out. The 300 doesn’t offer a back seat reminder.
The BMW 7 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 300 doesn’t offer a front passenger side knee airbag.
The 7 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 300 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 7 Series has standard Active Park Distance Control that uses rear sensors to monitor and automatically apply the brakes to prevent a rear collision. The 300 doesn’t offer backup collision prevention brakes.
The 7 Series’ standard lane departure warning system alerts a temporarily inattentive driver when the vehicle begins to leave its lane and gently nudges the vehicle back towards its lane. A lane departure warning system costs extra on the 300 and is only available on 300 Touring L/S.
The 7 Series offers an optional Surround View to allow the driver to see objects all around the vehicle on a screen. The 300 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.
The 7 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 300 Touring L/S offers a blind spot warning system.
To help make backing out of a parking space safer, the 7 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 300 Touring L/S has a rear cross-path warning system.
The 7 Series’ driver alert monitor detects an inattentive driver then sounds a warning and suggests a break. According to the NHTSA, drivers who fall asleep cause about 100,000 crashes and 1500 deaths a year. The 300 doesn’t offer a driver alert monitor.
Both the 7 Series and the 300 have standard driver and passenger frontal airbags, front side-impact airbags, driver knee airbags, side-impact head airbags, front seatbelt pretensioners, plastic fuel tanks, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, daytime running lights and rearview cameras.