Here's my opinion ... If you are required by law do display a front plate (Here in PA we are not) just go ahead and drill a couple of small holes in the front bumper cover. There are two tiny dimples which I assume are for locating the recommended holes for a front plate. Any type of clamp-on plate holder will probably do as much damage to the plastic as a couple of screw holes.
I looked around and there don't seem to be any "no drill" plate frame options specifically for the EC, but you could probably get one for a Porsche or Miata and adapt it. They sell between $80 and $90.
I looked around and there don't seem to be any "no drill" plate frame options specifically for the EC, but you could probably get one for a Porsche or Miata and adapt it. They sell between $80 and $90.