Loose air-blocking panel at right side of radiator--rattle, squeak, buzz?

[dogsridewith]

(Loose air-blocking panel at right side of radiator--rattle, squeak, buzz?)

Moves freely vertically an eighth or quarter of an inch. Larger than the panel on the left side of radiator, which seems tight.
Will put a piece of foam under it to take up play, pending suggestions. Curious if this involves broken or missing clips or trim, etc. (Mine had a right headlight replacement, so maybe something got altered.) Definitely something to check on any Yaris as a potential noisemaker.

[CTScott]

That is a large plastic piece, which should not have been touched when the headlight was replaced, but you never know. It just snaps into place.