The quick way is---In C4D go into preferences (Ctrl-E) and change the obj scale to 1000 for import and export, then open poser and export a figure (any adult will do) making sure you have only  the figure selected and only select the weld body part seams box.

Now open your van in C4D and import the poser figure, scale the van to match the figure, then delete the figure and save, now delete all the moving parts and export the bodywork, revert back to the van and delete the bodywork and all the moving parts but 1 (lets say left door), repeat this till you have the main van and and all the moving parts as seperate parts then start importing them into poser (make sure you unselect all boxes on import) ---once you have everything in poser you can start parenting and moving the centers so the doors work properley..........Steve