Johnny is notably the only one of the group (Luca, Tuna, and him) that has no speaking roles. If the player fails the mission Taking in the Trash by the means of Luca or Tuna dying, he says nothing to Niko and leaves the vehicle.
As mentioned above, Johnny has no speaking roles directed at Niko. However, if he is shot he will use the taunts of a random Mafioso found in Little Italy.
According to game files, Johnny's beta name was Vinny.
In Meltdown, Johnny sits behind Tuna (who is in the driver's seat). In the gunfight, he uses a SMG. He wears a brown jacket with a light brown sweater underneath, as well as black trousers and a belt.