If you can still find it somehow, ASH WASTES was an attempt to get the Necromunda out of the hive setting.
In it, there were/are numerous vehichels and conversion Ideas right out of Gorkamorka.
BOTH games mesh entirely together, save the teef thing, which by all accounts can easily be part of the
RPG elements.
Teef/ creds can easily work out in the zones, especially when people/fings trade anything of value.
As for directions to find this stuff,
1. There was a batch of rules over in the specialist games site, except now that
GW has made the grade, yet again of jacking it up, it takes some looking.
2. The Necromunda Magazines- these old tomes have multiple articles about the ash waste zones, the rules for the buggies, etc.
3. I've been seeing some of Grey deaths stuff that he references, and there is alot of the same for this, as well.
4. Ms. Dewey knows all, Ask her.