Doom Buggy is the show name for Disney's OmniMover system. It was initially developed for the "Adventures in Inner Space" attraction by a team led by Bob Gurr.
The cars, linked together, move forward via a 12-volt electric drive train. The vehicles themselves have no means of locomotion. They are driven by a series of ten motors located throughout the ride. Each car can also be rotated 180 degrees--from facing forward to facing backward.
This rotation, combined with scalloped design of the car, allows the designers to control what the guests see at any given time.
Each car is also equipped with 3 speakers. The sound (which is not stereo, as commonly reported) is transmitted to odd-numbered cars via a narrow band transmitter. The signal (once received) is then passed on to the even-numbered car behind it.
Disneyland's Haunted Mansion has 131 cars, with a guest capacity of 2,618 guests per hour, granting 2.25 guests per car, assuming no ride stops (wheelchairs or slow guests). A typical hour at full capacity is 2000-2400.
Walt Disney World's Haunted Mansion has 160 cars, due to its longer track, with a guest capacity of 3,200 guests per hour.
Keep your hands and feet inside the Doom Buggy at all times.