[Leonardo]

OP, If you use foam, I would highly suggest using low expansion spray foam. If you use the 3X expansion, it can warp the trunk lid. I watched my friend destroy his trunk lid by using the stuff that expands too much.






Edit: Saw the underside photo. Forget expansion foam. Either: Remove the wing and sell it. Use money to fix holes in trunk. OR Take the wing off, build underside brace plates, do body work on the damaged area - then paint, now re-install the wing. OR Get a new trunk lid and start over. Good luck!