[Bethpage]

...........I don't know how far it will get you but it's worth attempting to remove the rear seat base's from the car and it might give you some more room to get the seats down or out somehow.

Locked the keys to a Buick hire car in the trunk while in the States once. That necessitated the removal of the back seats, squab & back rest to retrieve them, cost me some beers that night for my fellow co-workers. Never shut a trunk (in the States or Canada for that matter) since without knowing that the keys were in my hands or on my person