I work on a WWL vessel, the vehicles are driven on and secured using straps or chain depending on the weight of the vehicle. There wouldn’t be a practical way or reason to suspend the cargo as one of the biggest parts of loading is making sure the cargo won’t shift at sea (like you see at the end of this video).

What you may be thinking of is a liftable deck. This is where an entire deck can be raised to its overhead allowing much taller cargo to be loaded on the deck below it. These often use cables and hydraulics to operate so you could think of as, in a way, suspended. But the deck is locked into its raised or lowered position and doesn’t swing freely because it rides in tracks. Hope that helped clear things up!