oesman

It's bothering me a little that it doesn't seem like it's flush with the edges of the trunk.

Buckingham

Probably to give room for expansion and contraction based upon temperature.

oesman

If it's really CF, that seems unlikely since it has a very low coefficient of thermal expansion. It should be much more resistant than the rest of the material the car's panels are made of, the trunk itself would expand before the spoiler.