I'm in position with the RC-chopper, all systems are go to neutralize their surface to air defenses. We're going to need free reign of the skies during the heist.
― Bentley explaining to Sly why he has to destroy Rajan's Jeep[src]
Bentley needs to destroy an enemy jeep so that he and the gang will have clear skies for the heist.
As the jeep starts it's route, Bentley launches his RC chopper from its position on top of a tower. In order to neutralize the air defenses, Bentley hovers his chopper over the jeep to bomb it. It isn't too hard to destroy, just as long as he avoids the missiles by making sharp turns. Once the jeep is destroyed, the gang will have no issues during their heist.