Revealing mistake: While Akeem is getting his hair cut, you can see the reflection of the white character he plays in the mirror. It is quite obviously a stand-in, with a fatter face and different glasses. (00:33:45)
Revealing mistake: When in the barber shop, the elderly Jew (played by Eddie Murphy) is shown in one shot. Then when the camera changes positions, he is shown again in the background. It is an obvious double, and doesn't look anything like Murphy did in the earlier shot.
Answer: That is the taxi medallion, a license for the driver to operate the yellow cab. All NYC yellow taxi cabs must have one of these metal plates (there are different types) affixed to the hood of their NYC yellow taxi. This particular type is the red apple medallion.
Super Grover ★