The end of the movie suggests that Pattons wife left to have dinner with General Hap Gay before Patton died. Patton's wife was in fact present when he died, and spoke his last words to her.
After his wife leaves to eat dinner with General Gay, Patton wakes up, and says "Papa" before passing away. His actual last words were "It's too dark, I mean it's too late".
The general celebrates his birthday, and it looks like the next day he has his accident. This is evidenced by the soldiers in the truck singing the tune that was played at the party, "Chicory Chick". General Patton's birthday was on November 11th, and the accident happened on December 8th. It couldn't have happened the way it was depicted in the movie.
Parts of the films were shot at Harlaxton Manor in Lincolnshire, UK, although since it is supposed to be in Bavaria, the Alps are shown in the background. In one scene, they failed to insert the Alps behind the manor house.
An army official tells the assembled reporters, "We've tried to accommodate the media." The term "media" to refer to journalists wasn't used before the 1960's.