The three cars used in the comparison testing were the Peugeot 207 CC, the Citroen Pluriel and the Mini Cooper convertible. The three cars were chosen as representative of three levels of available protection: the Citroen has effectively nothing in the way of added rollover safety, the Mini has passive roll bars, and the Peugeot has an active roll bar system.
ADAC gave the win to the Peugeot 207 CC for its relatively good protection of rear passengers, thanks to the active roll bar system. Unfortunately the A-pillar support failed under the load and therefore front occupant safety was compromised. The Mini had the best results in regard to the A-pillars, but seatbelt geometry problems allowed the passenger to slide too far out of position, greatly increasing the risk of head injury during a rollover, and the built-in passive roll bars are only good for people shorter than 1.75m (5ft8in). The Citroen fared worst of all, with collapsed A-pillars, poor seatbelt geometry and roll bars inadequate to protect all but the shortest of occupants.
The bottom line of the test results is that none of the cars is really safe during a rollover crash, and in order to remedy that problem, makers will need to augment the A-pillar strength, increase roll bar clearance and improve the ability of seat belts to hold passengers within the protective shell provided by those improvements.
The ADAC also suggested traction control (ESP) could help reduce the incidence of rollovers, thereby avoiding the problem altogether. The EU's recently announced plan to require ESP should dovetail nicely with the findings, and should make buying a small cabrio somewhat less risky in future.