Theres probably a way to map things in carrea, but I do know it does odd things with material names and groups whern exporting .OBJ's.   

So I give instances and objects the same name, delete all the materials in UV mapper then use a combination of  Lithunwrap and UVmaper to map things correctly.

Works well and even quite complex stuff can be mapped very quickly.   
 

Pinky - you left the lens cap of your mind on again.