Just like to add, if its cracked into the urethane you really need a plastic welder like a Polyvance unit or something similar. If you just fill the crack, it could break out again.
I have a spare bumper cover for both my 91 and 94 TAs. When they reach the point when there's too many rock chips or stains from bug juice i just install a "fresh" one and take the one in removed to my painter.