2 Tickets to the Gun Show was a variant of the Warthog intended for inclusion in the canceled Untitled Halo MMO. It was apparently to be used by law enforcement, as evidenced by the word "POLICE" printed backwards on the hood of the vehicle.
As can be seen in the concept art, there appears to be two seats mounted on the back of the vehicle, each with its own turret. This brings the capacity of the Warthog up to four. Its weaponry may not be equipped for vehicular battle, such as that of the standard military Warthog, but it would be capable to engage riots, shoot-outs, and other civilian uprisings.
While developing the Halo games, Bungie, 343 Industries and Ensemble Studios have had to cut some content, such as vehicles, gameplay, and story elements, from the final products. Much of this content has been confirmed by videos and commentary in special edition DVDs, interviews with developers, and released concept art.