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 S90 are reminded to check the back seat if they opened the rear door before starting out. The A6 doesn’t offer a back seat reminder.
The Volvo S90 offers optional built in child booster seats. They’re more crash worthy than an added child seat because of their direct attachment to the seat. Audi doesn’t offer the convenience and security of a built-in child booster seat in the A6. Their owners must carry a heavy booster seat in and out of the vehicle; S90 owners can just fold their built-in child seat up or down.
The S90 has a standard Whiplash Protection System (WHIPS), which use a specially designed headrest to protect the driver and front passenger from whiplash. During a rear-end collision, the WHIPS moves the headrests forward to prevent neck and spine injuries. At the same time the pretensioning seatbelts fire, removing slack from the belts. The A6 doesn’t offer a whiplash protection system.
The S90 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 A6’s blind spot costs extra.
To help make backing out of a parking space safer, the S90 has standard Cross Traffic Alert and Braking Intervention automatically engages the brakes to help avoid a collision. Audi charges extra for Rear Cross-Traffic Assist on the A6.
The S90’s 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 A6 doesn’t offer a driver alert monitor.
Both the S90 and the A6 have standard driver and passenger frontal airbags, front and rear side-impact airbags, driver knee airbags, side-impact head airbags, front and rear 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, post-collision automatic braking systems, daytime running lights, lane departure warning systems and rearview cameras.