My theory as to why there isn't much activity in the van:
A. The kidnapping itself kind of stifles conversation beyond general confusion as to what's going on. After getting drugged and kidnapped, you don't generally wake up a decide now's a good time to talk to someone about the crazy week you've been having. :P
B. Everyone (except sandman Adam) in the van has pretty passive powers. Patt's power's "off" at the moment, super luck and regeneration aren't very noticeable at first glance, and Adam's sand can't be easily traced back to him. This prevents random fireballs from starting a conversation.
I recommend having an NPC come to the back of the van and (hopefully) starting discussions about the off things that happened after the bus crash.
Of course, these are just speculations on my part, so take them with a handful of salt.