Okay, gotta a ask the dumb question. Why do you want to do this???
I get that you want to customize the vehicle - got it. But a grill from another year that doesn't quite fit - don't get it.
Many vehicles, trucks especially, have customized grill instead of the original so I can see how one might want a different appearance about their car. Is there not other options for Odyssey? I simply don't know.
In fact, there are several threads about putting 2014 parts onto 2011~2013 (e.g., LED tail light assembly) - again, why?
Completely understand upgrading for performance parts or something better than factory but to go through the change just for new model year parts - don't get it still....