2017 Impala trunk leak, what plug is this?

Hello all,

I noticed some water in the trunk of my 2017 Impala.
Pulled back the covers and no obvious signs at the tail lights,
I think they fixed the tail light gasket problem by 2017...
Looking around I found an oval hole on the outside of the trunk
lid gasket, see photo below. That hole goes right into the trunk,
right above some computer module. I seen the same size hole
on the side behind the tail light. I can't seem to find the number
on this part to replace it, can someone tell me this part#?
I found part# 15259076 but from the photos this don't look right.
I need an oval plug. Anyone know what the correct plug is?

Thanks for any help,
Jim