I created a new material and provided a converter to Kam's material
Not all things are supported yet but you should be able to import pretty much any GTA dff from any platform. That does *not* include iOS LCS dffs (yet) as they're not proper dffs.
Note that models exported by Kam's script don't get different materials per mesh as Kam exports material IDs wrong. I will correct this in a future version but was too lazy to do it now.
EDIT: As of version 2.0 there is an exporter now as well. Not everything that is imported can be exported yet, but I wanted to get this thing out.
See the README for some more information.
Version 3.1b - not tested a lot. please report bugs.
The "convert hierarchy" option should be left on. When exported in world space the official RW exporter rotates everything so max's z-up will match RW's y-up world. Models that were originally exported from max's biped objects are exported "lying down" when not exported in world space. This option rotates them so it'll look nicer.