Many Years of safety research by Opel into all possible types of accidents and crash testing resulted in a new construction with a reinforced passenger safety cell for the Opel Kadett C.  




To enable them to develop this safety cell Opel built a vehicle which was externally a Kadett C called OSV40. This car withstood a head on impact of 40 km/u without damage to the passenger cell. It also withstood a roll over test and side impact with very little damage to the cell.  Not all the information gained using OSV 40 was used in the final Kadett C, but laminated glass was used for the windscreen and the petrol tank was placed above and between the rear wheels an area almost never damaged in an accident. 




Dozens of crash tests were carried out on the Kadett C to ensure that the collapsible zones at the front and rear of the vehicle collapsed along designed lines. 




Additionally in a frontal impact there was a collapsible steering column, the roof and doors were reinforced to help with head protection and generally there was much more use of soft materials on the inside.




Three point seat belts were installed to prevent movement in an accident.