there are actually only two different bumpers. the MP3 and the mazdaspeed are the exact same, with the exception of some separate add on pieces. (like the 03.5 mazdaspeed lip and fog delete panels) the protege5 bumper has side lights, since the headlights dont have any, so has extra holes on the side for those, which the mp3 / mazdaspeed bumper does not have.
so, actually, besides the holes on the sides, all three models have the same bumper and are interchangable.