I suggest that AFTER you clone the parts and mirror them, get rid of the animations of the cloned parts and redo them. There is a reason:
A lonely animated object that has been cloned might rotate or move in a not-so-mirrored manner as it should [ex: left landing gear - that's suppose to move forward - moves backwards instead].
A object that is linked and cloned to an animated object might move or rotate in relation to the OLD object and NOT the cloned object. [ex: a door handle - used for the left door - might moved whenever the right door opens even if the left door is stationary].
So again, redo the animations for the newly cloned objects and remove their links as well. Then start animating them again. Try it, you might save a few aspirins.
