The ArrowBATic prototype car has a pair of gigantic steel bars that wrap around the track in the same manner as the safety pins on the Arrow suspended coasters. I believe Arrow engineer Alan Schilke referred to those bars as "ape hangers". Since the axles ride below and outside the track, Arrow likes to provide a failsafe backup...always has, and in fact, that's one of the reasons most Arrow coasters have the guide wheels and axles inboard of the rails.
To the best of my knowledge, the B&M inverted coasters have no such safety bar arrangement on them. They also don't have safety cables between the cars.
Interesting: At IAAPA '99 I stopped by the Arrow booth and looked at the ArrowBATic car and noticed the ape hangers. I asked Alan why there weren't any similar anti-derailment means on the Mad Mouse car, but he didn't answer that one. Showed me lots of details on the suspended ar, though!
--Dave Althoff, Jr.
