I let my late 2010 MacBook Air slide off a counter -- argh. It fell on a corner and bent the back cover. It was warped just enough to make a gap in the case and a sharp point near the vent. But, hey, it still worked at least.
Was able to bend things back into place fairly well, so there are scratches now, but no gaps! Also there is a small post inside to keep the cover off the electrionics. I was able to make sure this still had clearance, as if not a short would have been possible.
Since the cover is brushed aluminium, scratches can't be buffed out -- it looks shiny then. Also, the cover is so thin, that I could have used pounding and a ball tool to get the proper curve exactly, but was afraid to then extrude it out of shape. In any case the bening was enough to make it fit.
Also, was going to buy just the pentalobe tool, but the driver set wasn't much more expensive. Now I can get into any device!