Corrected entry: As the family is driving through New York, the radio station that's playing advertises itself as "music from the '60s, '70s, '80s, and '90s." This wouldn't have been possible since the movie is set in the 1980s.
Corrected entry: In the carnival scene, at the game booth where the father is trying to win the ET doll for his youngest daughter, in the shot where they put the rest of the rent money down for his last chance, some of the bills in the pile are the newer, larger portrait bills. The movie takes place in the early 1980's. The redesign of the U.S. currency didn't start until 1996.