hahahaha! i wondered the same thing myself a few months ago. it fell out while i was rewiring some junk and had no clue how it went back in. until this thread, i totally forgot 'bout it.
Wow, thanks for the pic. Just did this for the first time, and was giving myself fits trying to figure out where that damn clip went. Great info here!!!!
Thank you for posting that pic, was kicking myself trying to figure out how exactly that should be put back together. Popped out today while installing new HID lamp... now to go finish the job so I can bring back some pics to post!