It doesn't have to do with regulations.
As you would expect from an absolute EV flagship with a six-figure price tag, the Mercedes EQS is brimming with tech. From its powerful dual-motor AWD setup to the 56-inch Hyperscreen, the fullsize luxury sedan is worthy of its status as the S-Class of electric cars. That said, some would argue there's one glaring omission – side cameras.
Daimler CEO Ola Källenius explained in an interview with Automotive News Europe why the R&D team behind the EQS decided to stick with good ol' side mirrors. Long story short, Mercedes was concerned that seeing what goes on behind the vehicle would've resulted in motion sickness. Not only that, but the electricity needed to power the cameras would've almost negated the aerodynamic benefits created after replacing the bulky mirrors with tiny cameras.
Even with chunky side mirrors, the Mercedes EQS is still the most aerodynamic series production car ever built. With the 19-inch AMG wheels and the Sport mode activated, it has a drag coefficient of only 0.20. That’s still more than the slippery Volkswagen XL1 (0.189), but the diesel-electric hybrid was a limited-run vehicle with just 200 units built. The General Motors EV1 had a Cd of 0.19, but that one was a rare breed as well.
Ola Källenius went on to say Mercedes is not keen on introducing "technology for technology's sake," but he is open to the idea of replacing the glass with cameras one day, provided these systems will improve in the future. It's worth noting parent company Daimler has already implemented this feature in its big trucks such as the Actros where the setup is known as MirrorCam.
For the time being, Mercedes thinks the tech is not suitable for passenger cars:
"The studies so far have found that a not-insignificant portion of customers, when they have a screen inside the car watching what's happening behind them, they get motion sickness."
Some automakers would beg to differ considering the Honda E, Audi E-Tron, Lexus ES, and other models have digital mirrors. One method that might please both worlds would be the system used by some Hyundai and Kia models where the traditional side mirror is accompanied by a camera that shows its feed in the instrument cluster. It kicks in whenever the driver activates the turn signal and it effectively eliminates any blind spots.