MERCEDES-Benz is fitting £800 worth of special stability equipment and new tyres to the A-class after Swedish journalists managed to turn over a car at less than 40mph. The incident happened when the testers were performing the so-called 'elk avoidance test' - a series of severe swerves through cones on a test track. Mercedes-Benz said the exercise was an extremely severe test which no driver would perform under normal conditions and that it was perfectly satisfied with the safety of the A-class, but announced immediate modifications to the radical supermini.

From February, all A-class models will be fitted with Mercedes' computer-controlled electronic stability programme (ESP) and new specification tyres at no extra cost to the customer. Cars already sold in Germany will be recalled and the modifications carried out without charge. The timing of the incident and subsequent announcement, which was quickly pounced on by the majority of the European media, is unfortunate - coinciding as it does with the A-class fleet launch in the south of France.

A Mercedes-Benz spokesman said the ESP system, which is an £820 option on other Mercedes models, would prevent the A-class getting into the situation where a roll was possible. The system works by constantly monitoring the car's wheels independently and either reducing the power or braking the wheel when it detects abnormal behaviour. Modifications will not cause delays to the UK launch in June.