51mm
Rear seats are usually top priority for S-Class owners, and the 2021 model gets it right with a lounge-like twin-seat setup with soft pillows on the headrest. Also, rear-seat occupants get their own entertainment system and a tablet through which they can access most of the features, including the massage function, climate control, infotainment system, and ambient lighting.
The S-Class scores brownie points on the safety front as well. Passengers sitting at the back get first-in-segment rear seat airbags placed behind the front seats. In the case of a mishap, the two airbags open up, protecting the rear-seat occupants from head and neck injuries.