Is the World Ready For a Car Without a Rear Window?

Source: Slashdot

Overview

Polestar’s new Polestar 4 replaces the traditional rear‑view window and mirror with a live video feed from a wide‑angle camera. The high‑resolution display (1480 × 320 px) provides a “panoramic view of the outside,” offering better visibility in darkness and rain, according to Polestar’s website.

Technical Implementation

• Rear‑view camera feed: The feed comes from a wide‑angle rear camera and is shown on a dedicated high‑resolution screen that mimics the shape of a conventional mirror.
• Additional sensors:
  • Four short‑range cameras for 360° coverage.
  • Short‑range ultrasonic sensors.
  • A total of 11 exterior cameras, 12 ultrasonic sensors, and a mid‑range radar for threat detection and intervention.
• Display features: The image is mirrored, has a suitable focal length, decent resolution, and low‑light sensitivity. Graphical overlays and warning tones help drivers judge distances.
• Auto‑dimming: The system includes advanced auto‑dimming algorithms for the rear‑view display.

“Visibility in the dark and in rainy conditions is also vastly improved.” – Polestar

The design also improves aero efficiency, reducing drag and turbulence—critical for an all‑electric vehicle where aerodynamic drag directly impacts range.

Driving Experience

In practice, the rear‑view camera works as well as—or better than—a traditional mirror. The display’s familiar shape and mirror‑like imagery make it easy to trust for distance judgment. Drivers reported that the system feels natural, especially with the added graphical cues and audible alerts.

Historical Context

• Sports cars have long treated rear‑view mirrors as decorative. The 1974 Lamborghini Countach LP400 originally envisioned a rear‑facing periscope in the roof.
• A memorable pop‑culture reference appears in The Gumball Rally (1976), where Raul Julia’s character removes the mirror from his Ferrari Daytona, declaring, “The first rule of Italian driving: What’s behind me is not important.” – YouTube clip

The Wall Street Journal notes that typical rear‑view windows sit about five feet off the ground, making low objects (e.g., traffic cones) invisible until roughly 35 feet away.

Safety and Assistance Features

• Speed‑limit recognition: The system reads speed‑limit signs and displays the posted limit; exceeding it triggers an audible warning.
• Adaptive headlights: Built‑in camera sensors in the windshield automatically switch between high and low beams when they detect oncoming traffic or taillights.
• Airbags: Seven airbags are deployed in the event of a collision.

For more details, see the Polestar 4 specifications: Polestar 4 and the rear‑view HD camera description: Rear‑view HD Camera.

Thanks to Slashdot reader fjo3 for sharing the article.