Not to mention that it would mess up the clearances, the passenger restraint mechanisms would not function properly, the lift mechanism would not work, the advancing wheels would not work properly, the brakes would not function, the track gauge does not match, the cars would cause damage to the sensors and other equipment mounted on the track, and the larger cross section of the car would make wind a much bigger problem than it is now. Oh, and the ride would probably *deleted*.
Apart from that, I don't see any reason why that couldn't happen... :)
--Dave Althoff, Jr.