The whole issue is mostly political.
No one official has yet discussed that in AZ (since almost every one of these incidents has been in that state alone) may be contributing to any potential problem with the way they install Police equipment in the trunk. One Story I read had the AZ spokespeople saying that equipment inside the trunk had pierced the trunk wall. nothing more has been said on that.
I've read posts by police who have claimed a half dozen tanks in new Police cars had to be replaced because their installers had run screws into the gas tank itself.
One person who perchased a used Inteceptor complained of a gas smell. He discovered that a screw from old installed eqipment had at one time pierced the fuel vapour return line.
Even after their meeting with Ford, where an agreement had been reached for Ford to test fuel bladders, AZ pushed the issue with more negative press realeases, and the TV release that was picked up by CNN and NBC. Why continue to do this when you are otherwise seemingly working mutually to a solution?
AZ has an alternative, they are supposedly ready to purchase new vehicles. There are other optons, but they still seem to want the Fords. Despite the 2003 having solved the problem of certain items potentially piercing the tank, they still cancelled orders. Why?
One gets the impression from reading what AZ has to say that the fuel tank is located under the trunk, directly behind the rear axle, and in front of the rear bumper. It isn't. It is in fact in front of the trunk, mostly above the rear axle, and probably the farthest distance forward of the rear bumper than many vehicles. the energy required to crush the rear of the vehicle that far so as to crush the tank is absolutely enormous!
Ford does rear collision testing, to a standard of 50 mph, which is higher than most manufacturers, and higher than the government requirement.
From what I have read, the collisions involving the Police vehicles have been all high impact, in excess of 75 mph, one a stated at least 100mph. These are hardly common or 'simple' rear collisions as portrayed by AZ