The mode dial cap got detached from my 5DIII and lost. It's a pain replacing it because the cap itself is not a Canon part and the whole top unit has to be replaced at a cost of more than £200. I wasn't worried about the cost as the camera is still under a 1 year warranty and I had taken out 3 years accidental damage insurance as well (which is very rare for me to do). Because of the hassle of losing the camera while the repair was taking place, I tracked down a dial cap to glue on, due to arrive on Monday (which it did). But, on Sunday, when walking along with a strap attached to the lens over my shoulder, the body fell off, cracked the top unit and spewed out all of the dial components. So the dilemma is over - the top unit is being replaced under insurance. The camera is still working, the top unit having acted as a crumple zone.
It's back to the 7D as a great back up.