Heads Up! Convertibles have pop up roll bars. These things are designed to pop out (in 1/5 of a second) behind the back seats to protect the occupants in the case of a roll over. Imagine holding c-spine behind a patient and having one of these deploy into you.
Disconnect the battery, and the electronics that activate the spring loaded release cannot be engaged. Just another reason to Disconnect The Battery Every Time! These roll bars are only supposed to deploy when the vehicle reaches an extreme angle, but after a crash we cannot count on any system working properly!
Above is a screen shot of a 2009 C70 Volvo from Crash Recovery system. Notice the bars behind the rear seats.