HANOVER, Germany -- You might not see them, but you can feel them: Shock-absorbers play a vital role in keeping your car safe, and should be checked by a qualified mechanic regularly, DPA quotes German Vehicle- Testing Agency TUV as saying.

Damaged or worn absorbers can cause a big deterioration in roadholding, with wheels no longer in contact with the ground on uneven roads. That means both braking and steering are endangered.

Typical signs of worn absorbers are that a car pitches after crossing a corrugated surface or develops understeer on bends.

According to a survey of TUV stations in Germany, 18 per cent of a sample of 4,000 cars failed their road-safety tests last year because of shock-absorber defects.