J. Daniel Atlas: Come in close. Closer. Because the more you'll think you see, the easier it'll be to fool you.
When the agents arrive at the Four Horsemen's apartment to arrest them, in the shot where Dylan exits the car, the reflection of the boom mic is visible in the other car's window. Try not to be confused with the bird flying around in the reflection - the mic is still visible next to the bird.
When the remaining Horsemen greet New York, there is graffiti under their stage that matches their symbol. It's almost in the center.