Like the S-Class Saloon, the new Coupé model no longer has a single bulb on board. Over 450 LEDs are now responsible for illuminating the road, the vehicle, the interior and the luggage compartment. Depending on equipment, these include:

The new energy-saving LED low-beam headlamps, for instance, require 34 watts to produce the same light output, making them notably more efficient than halogen (120 watts) and xenon light sources (84 watts, all figures per vehicle). This means that it is possible to save up to 0.05 litres of fuel per 100 kilometres, or 2.1 grams of CO₂ per kilometre, compared with a vehicle with halogen low-beam headlamps. New, powerful single-chip LEDs and a newly developed projection module in the headlamp, where light rays are diverted, reflected and projected outwards, contribute decisively to the increased efficiency.

Optionally available expressive headlamps, each featuring 47 Swarovski crystals, lend the S-Class Coupé a uniquely striking appearance. 17 angular crystals form the flare-shaped daytime running lamps, with 30 round-shaped crystals making up the turn indicator lamps.

Standard equipment for all S-Class Coupé models includes High Performance LED headlamps, the Intelligent Light System and Adaptive Highbeam Assist Plus. Night View Assist Plus with pedestrian detection and spotlight function is available as an optional extra.

An emergency light function prevents failure of the entire front or rear lighting. By way of example, a certain number of lights are switched on if a bus system or a control unit fails. Safety is further enhanced by the standby light function: if light functions relevant to safety fail, other functions are activated to replace them.

Adaptive Highbeam Assist Plus allows the high-beam headlamps to be kept on permanently while driving by masking out any other road users detected in the beams' cone of light. If the camera-based system registers either oncoming traffic or vehicles ahead, it will adapt the light distribution according to the traffic situation when high beam is switched on. Consequently, the driver can leave the high-beam headlamps on at all times and use their full range without irritating or even endangering other road users. There is no need to switch them on and off manually, resulting in a significant increase in the overall driving time with high beam.

Adaptive Highbeam Assist Plus likewise makes use of the stereo camera also employed by other assistance systems. If its image recognition algorithm picks up a vehicle that is oncoming or driving ahead, it actuates a mechanism in the headlamp module. This masks the section of the LED headlamps' high-beam cone of light where there are other vehicles to prevent their drivers from being dazzled. If road users are detected outside the area that can be masked – for instance when cornering with multiple vehicles in the headlamps' beams – the system will switch to the familiar function of headlamp range control using the low-beam headlamps.

Possible backglare caused by increased use of the main beam and highly reflective signs at the side of the road is also detected and eliminated by dimming the headlamps accordingly.

The new S-Class Coupé shows itself to be highly considerate of its fellow road users in another way, too: thanks to multi-level functionality, the brake lights and indicators are operated at varying intensities depending on the current driving state and the brightness of the environment (day/night).

If the Mercedes driver presses the brake pedal while stopped at traffic lights at night, for instance, the brightness of the brake lights will be automatically dimmed to avoid dazzling anyone behind. The light distribution is broadened to ensure the lights do not become too dim and that they continue to fulfil all legal requirements, of course.

Night View Assist Plus is capable of detecting not just pedestrians in potentially hazardous positions in front of the vehicle, but large animals too. As a third-generation night vision system, it issues a warning in particularly relevant situations (darkness, unlit roads at speeds exceeding 60 km/h) by automatically switching from the speedometer to a brilliant night view image in the instrument cluster display. Pedestrians or animals detected ahead are highlighted in red in this image.

In such situations the spotlight function is additionally used to repeatedly flash pedestrians in the warning zone by means of a special module in the front headlamps. This attracts the driver's attention to the danger, and the person at the road edge is warned at the same time. Animals are intentionally not flashed, as their reaction to light impulses is unpredictable. The greyscale image can be switched on at any time; pedestrian detection, and the corresponding highlighting, are now also available in urban areas during darkness (illuminated roads, speed less than 60 km/h) if the greyscale image is activated permanently.

An additional (long-distance) infrared sensor in the radiator grille helps to enhance the proven Mercedes-Benz night-vision technology. This enables pedestrians to be detected at a distance of up to 160 metres, and animals such as deer, horses or cows at up to 100 metres. Two separate light sources in the headlamps illuminate the road ahead of the vehicle with invisible infrared light. A (short-range) infrared camera behind the windscreen near the rear-view mirror is able to generate a brilliant greyscale image in the instrument cluster display. This can also be displayed permanently if required by pressing a direct-selection button.

Good vision also is ensured by MAGIC VISION CONTROL. The system cleans the windscreen without the splash of water that usually briefly impairs the driver’s field of view in the case of conventional windscreen washing systems. With MAGIC VISION CONTROL, the fluid is supplied to the windscreen by means of water guides integrated on both sides along the wiper blade and minute spraying holes. MAGIC VISION CONTROL operates based on the vehicle speed and takes account of the outside temperature. Plus the contact surface of the wiper blades on the windscreen is electrically heated as standard to prevent the wiper blades from getting stuck in snow.