The SLK has been on sale since 1996. It proved a very strong car in frontal and side impact testing, suffering little damage to the cabin, while the doors remained straight and substantially undamaged. The car was tested in the frontal crash with its top down to give worst-case results. For the side test, the top was left up to check for the risk of head injuries. Although the car was tested without child restraints, one can be fitted to the passenger's seat so its fitting and labelling requirements were assessed. Pedestrian protection was poor.
Front impact
The airbag cushioned the driver, but his head moved to the left and turned through 90 degrees, which was a worry. This was not helped by the movement of the steering wheel and seat, the latter caused by distortion around the centre tunnel. The driver's airbag was relatively 'stiff' and that, and the seat belt, put his chest at risk. Unusually, the the driver's knee impact area was clear of objects that could harm his legs. However the supports for the glove-box on the passengers' side were judged to be too stiff. The floor to the right of the centre tunnel was badly deformed which might pose a threat to the driver's lower legs.
Side impact
The door-mounted side airbag worked well to protect the driver's upper chest. Loading lower on his chest and the abdomen was higher but still at relatively safe levels. The driver's head struck the roof rail, but not hard enough to cause concern. There was no padding or foam blocks in the door to add protection, which is unusual.
Child occupant
The SLK is a two-seater, so there was no room to test a restraint. One can be fitted to the passenger's seat, however. The car can recognise when a Mercedes-branded restraint is fitted and ensures that the passenger's airbag is disarmed. However this system does not work with other restraints, which may be hazardous if the driver is unaware of this. The warning on the passenger's sun visor was inadequate, but Mercedes say it is improving the labels.
Pedestrian
The bonnet proved to be fairly unforgiving in the adult and child impact areas. The bumper was also very hard, posing a hazard to pedestrian's lower legs. This is an aspect of design which Euro NCAP believes Mercedes needs to tackle.