Most of us drive our classic Ford cars knowing that they lack the modern safety amenities found on newer cars. We don't know your position on classic Mustang fuel tanks, but we do know that no vehicle type can survive every type of rear impact collision. If you race your car or are concerned that a rear impact may rupture your fuel tank, you may wish to replace it with a fuel cell such as this unit from Fuel Safe. It features an internal bladder that is flexible and will deform without bursting in most circumstances. The Fuel Safe Mustang fuel cell for '65-'68 Mustangs is part number 423415 and costs $1,595.