Not to take sides here, but there is, I think, an issue with older designs (like the Crown Vic and the Mustang) and some newer SUV's that have the fuel tank right in front of the rear bumper. Absent a fuel bladder (as someone suggested), it is vulnerable, unlike many newer designs (like the Contour) that have the tank forward, basically under the back seat (so if the accident reaches the tank it will have likely already dispatched the occupants). That said, there is always the original Beetle where if you had a really good head-on crash the front-mounted tank would land in your lap and explode....
