As standard the SL features Active Brake Assist, known as COLLISION PREVENTION ASSIST PLUS in other model series. In addition to radar-based proximity warning and braking assistance by Adaptive Brake Assist, this Active Brake Assist system carries out autonomous braking to reduce the danger of rear-end collisions. If the driver fails to act when a risk of a collision is detected, despite the warning lamp in the instrument cluster and the intermittent audible alert, the system will initiate automatic braking. This significantly reduces the vehicle speed. At low relative speeds, this intervention may be sufficient to prevent a rear-end collision with slower-moving, stopping or stationary vehicles.

Optionally available for the SL is the Driving Assistance package Plus with stereo camera and in some cases new as well as improved functions. Overview of the features of the Driving Assistance package Plus:

The optional Parking Pilot can take the strain off the driver by helping them to search for a suitable parking space and making it easier to manoeuvre into and out of parking spaces with active steering intervention. A new feature is assistance with parking perpendicular to the road. The Parking Pilot includes six ultrasonic sensors in each of the front and rear bumpers which measure the size of the parking space when driving past it. In addition, the Parking Assist PARKTRONIC is also a part of the system. It provides visual and audible warnings of obstacles in front of and behind the vehicle, thus helping to avoid damage when manoeuvring.

For optimum visibility on country roads and motorways, when cornering and on bends, the standard-fit LED Intelligent Light System automatically adapts to all light and driving conditions. The LED technology features low energy consumption, a long service life and a pleasant white light which approximates the daylight spectrum. The five functions of the LED Intelligent Light System include motorway mode, cornering light function, camera-based active light function, roundabout light function and also the enhanced fog light function. On unlocking the SL, the welcome light also greets the driver with an exceptional lighting display: the LED fibre optics in the headlamps light up in blue after opening the vehicle and then transition to white locator lighting.

Anti-dazzle continuous high beam comes courtesy of the optional Adaptive Highbeam Assist Plus. When high beam is switched on, this system always makes the optimum headlamp range available. The driver can concentrate on the traffic and does not have to continually switch between low beam and high beam. Via a camera positioned behind the windscreen, the Adaptive Highbeam Assist Plus detects other illuminated road users, for example oncoming vehicles or vehicles travelling in front, and adjusts the headlamps independently to the new traffic conditions. A mechanism in the headlamp module masks the portion of the cone of light of the LED headlamps where there are other vehicles to prevent their drivers from being dazzled. The driver can therefore leave the high-beam headlamps on at all times and use their full range without bothering or endangering other road users. This function is active at speeds above 30 km/h when travelling in the dark on roads without street lighting.