If you're starting from a single OBJ, the "Helgard Method" of rigging a 
non-organic item goes like this:

1. Get the object scaled and located properly first, and be sure each 
   desired body part is a Group (g) in the object.  

2. Load the scaled obj in Poser.

3. Click on the Grouping tool, and hit the "Spawn Props" button in the grouping panel.
   This will separate all groups into individual props.

4. Hit the Delete key to eliminate the original.

5. Open the Hierarchy window and set up your parenting, using the
   logical structure of the vehicle.  The top item should generally be the
   chassis or body.  (Be sure you name the body something other than
   'BODY' though; call it mainbody or something like that.)

6. Select the top item and hit "Create Figure".

7. At this point you have a raw figure in the New Figures folder.  You'll
   need to edit the CR2 to change all 'bend 1' to 'bend 0', and you'll need
   to fiddle endlessly with the materials, of course.

A couple of helper scripts:

http://ockhamsbungalow.com/Python/CR2%20Helpers/makefurn.zip

MakeFurn changes the Bend in a cr2 and also strips out all the stuff
you don't need for a non-organic furniture or vehicle item.

http://ockhamsbungalow.com/Python/CR2%20Helpers/centerAndReplace.zip

CenterAndReplace locates the true "physical" center of wheels and
rewrites the origin.  This is needed because Poser's figure-create action
assumes everything is a critter with limbs, and puts the origin of all
parts where it would be on a leg or arm.

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