I did. Michael's limo was a '47 Cadillac. While they were walking, they passed a '47 Ford "Woody" station wagon. Obviously, not every car in America is the current year's model. But, the presence of two '47 cars in that scene could be consistent with Michael's having been back in America "for a year"--i.e., returned in '46.
Sonny: FYI, it was American car manufacturers' practice to introduce new cars in the fall of the previous calendar year. So, the '47 Cadillac and Ford probably first appeared in showrooms in mid- or late-October, 1946.