Originally posted by alfa75ts Never is bad word to use.
Indeed, but the USAAF were not formally used in a ground attack role during WWII. In Korea, yes. They did not do very well in this role because a bullet hole from small arms fire in the radiator is bad for the health of the pilot.
In the last stages of the war P-51 pilots did engage targets of opportunity on the way back from escort missions. There was the A-36 ground attack version of the Mustang, which also suffered from radiator problems. And the British used Mustangs for ground attack as you pointed out.
However, a P-51 in USAAF colors flying around Normandy on a ground attack mission was highly unlikely. It would have been a P-47 but there aren't very many left over in flying condition for movie producers to rent. It was aircolled, so no radiator problems. The loss rate was still quite high, though. By the time Korea came around, there were no P-47's left in service, so they had to make do with the P-51.
The P-51 'tankbuster' was invented by the dialogue writers to fit what was available for filming, it would seem.