almost lost mine as well.. luckily it came loose and fell into my camera bag.
on inspection, i see that the plastic pieces both sides, are just held in place by the rubber moulding. so if you keep yr OMD sideways in a bag, you will be trying to pry it out each time. better to keep it lens down in the bag.
btw, the EP-11 is S$30/- and it took me about 2 weeks to order thru Olym Spore.
oh on another subject related to our OMD, the rubber pieces protecting the hotshoe and accesories port comes in 2 parts, also just as easily lost. so i took them off and used a generic cover for the hotshoe when i am not using the flash.