When Bunz and Rashad are chasing Killer (the dog) down the street, a car door opens. Bunz and Rashad run into the door and flip over it onto the ground. As both characters are falling to the ground in slow motion, you can clearly see the stuntman who is playing as Jaime Foxx (Bunz) lose his hairpiece.
The impression Bunz was doing when Roshon was asking about a spare condom was that of Captain James T. Kirk of Star Trek, not Bill Cosby.