Visible crew/equipment: In the scene where the bus jumps the gap in the freeway, as the bus lands, the interior camera jerks down and we clearly see the cameraman's brown shoes.
Visible crew/equipment: When Sam is shot in the shoulder it shows a camera shot from the side of the bus going into a wall. In this camera shot you can see the shadow of the camera. (00:40:15)
Visible crew/equipment: A film truck with its crew and equipment is briefly visible in the reflection of a red van four shots after Jack directs Annie onto the shoulder (use pause to get a better look). (00:46:15)
Visible crew/equipment: After the bus exits the freeway, as it drives on the city's streets the forward looking street-level action camera is visible, mounted behind the tire. (00:49:05)
Visible crew/equipment: During the passenger transfers at LAX, a cameraman is visible through the bus doorway two shots before Annie glances over her right shoulder twice. (01:27:35)
Visible crew/equipment: When McMahon is giving Jack directions to the vacant 105 freeway, a well-dressed crew member wearing sunglasses and a big grin is visible sitting in the aisle of the bus. (00:49:50)
Visible crew/equipment: Right after the bus passes 50 mph and arms the bomb, filming equipment can be seen in the Jaguar's vent window reflection. (00:36:45)
Visible crew/equipment: When the credits are rolling, a crew member in a gray shirt on the lower left portion of the screen can be seen waving extras into the street. (01:51:05)
Visible crew/equipment: After Tuneman's Jaguar hits the water barrels, a film crew's truck can be seen out the bus's rear window just before the shot cuts away. (00:40:05)
Visible crew/equipment: When Harry's colleague hands him a printout of Howard Payne's newspaper article, a boom mic reflection is visible on the window right above the bomb schematic diagram. (01:15:15)
Visible crew/equipment: When Jack runs with the car after the bus just before yelling to the driver that there's a bomb aboard, when he does a risky maneuver, a cameraman and another crew member sitting on a tracking vehicle are briefly visible on the right side of the screen. (00:36:20)
Visible crew/equipment: When the guard walks past the pillars at the start, on the first pillar you can see a shadow made by the film crew. (00:03:00)
Visible crew/equipment: As Jack inspects the bus's speedometer for signs of tampering, a camera can be seen in a reflection on the window to Annie's left. (00:44:35)
Visible crew/equipment: As Harry walks out of the office after telling his colleagues to search for their mystery bomber via pension fund files, a boom mic pole is reflected in the left window when he says, "I've seen this a**hole." (00:55:25)
Visible crew/equipment: When Jack's Bronco weaves across two lanes of traffic on the highway seconds before throwing it in park to catch up with the bus on foot, a camera can be seen, mounted in the Bronco's back seat. (00:34:15)
Visible crew/equipment: A film truck is reflected in the bus's bumper when Jack exits and steps onto the Suburban. (01:11:15)
Visible crew/equipment: When Jack flashes his badge at Tuneman, a camera's shadow is visible on the pavement. (00:35:00)
Visible crew/equipment: When the bus is traveling on the shoulder, a camera truck is visible to the extreme left immediately before Annie asks whether or not she should stay on the highway. (00:46:35)
Visible crew/equipment: After Keanu steals Tuneman's car there is an overhead shot from a helicopter as he's trying to catch up. The shadow cast by the helicopter is visible at the beginning of this shot.
Visible crew/equipment: As the bus goes down the freeway, there's a shot of the police chopper following the chase. The movie camera chopper is seen above and to the right of the police chopper that is referred to as a news chopper, but isn't seen again.
Answer: Ventilation shafts or roof panels.
Toolio