The emergency Response Guides (ERG) that the auto makers are getting more detailed and starting to include extrication recommendations. The 2012 Toyota Prius ERG contains a recommended process to remove the roof when the side airbags are not deployed. A total roof removal is not recommended when the side airbags are not deployed. Toyota provides an image in the ERG to show where you should cut the roof. The roof center section inboard of the roof rails should be cut from front to rear. Make sure you remove all glass including all windows to ensure all broken glass is controlled and the patient is protected. Toyota states that the area highlighted inside of the roof rails in from store gas inflators and other hazards, but also peel away the trim panels to verify for yourself.
Cutting inside of the roof rails is a quick effective way to get access to the patient. A fast cutting method is to use a metal cutting circular saw. The Prius V has an optional transparent dark gray polycarbonate roof panel. Now I have never cut a polycarbonate roof panel, but its’ just a glorified piece of plastic so a metal cutting saw should work fine. One important note about using a metal cutting circular saw, once you start your cut watch for the pressure from the pillars pushing the roof rails toward the center of the vehicle. If you don’t follow me, let me switch materials. Imagine you are cutting a piece of plywood and halfway thru the saw blade gets stuck.