im not sure about the 2010s, but my 2009 didn't have a liner around the headlights, just "T" shaped rubber tabs at certain spots.
if theres a huge gap, i'd assume that they missed the headlight mounts on the frame. aside from the bolts that hold the headlight in place, there are notches and gutters that guide where the headlight assembly should slide and align into the body.
hope that helps
*edit: if you post up some pics showing the gap, it may be easier for us to help you out
