Continuity mistake: In the first 1968 section, where Noodles rents a car and drives back to his old neighbourhood, watch the background of the wide shot as he is stopping the car. In the close-up that follows when Noodles gets out, two girls have appeared, hanging around a doorway, who were not to be seen the moment before.
Continuity mistake: When Noodles is raping Roberta in the car, her socks are pale brown-grey, then camera angle changes, and they are black, and then they are grey-brown again.
Answer: It couldn't have been left there for that long. That's movie fiction. It would have been removed after a few days, maybe a week, then likely placed in "Lost and Found" for a period of time before being discarded or sold off.
raywest ★