The UZI that the gangbanger had looks like the real thing, but he's lying about it being "set to auto". Notice the ventilated barrel shroud? Those are only put on UZIs that have the 18" barrel that is the shortest legal barrel on the semi-auto guns. It doesn't do anything for accuracy or cooling, but it doesn't look as geeky as that long barrel by itself.
If that were a real selective-fire UZI, it would have the standard 10" barrel as no one makes a selective-fire UZI with an 18" barrel. Also, the selective-fire UZI fires from an open bolt, while the semi-auto fires from a closed bolt, so it's not one of these guns that you can convert to selective-fire or full-auto.