mounting rear wing on hatch

[Aaron]

i have bought an aftermarket fiberglass hatch wing and after speaking to a friend at a body shop need some advice as how to get it 'flush mounted', securely fixed and possibly with drainage.
from the sides where the wing wraps around the glass, we are unsure how blend the join into the body. using fiberglass would take a considerable amount and it could possibly crack in the future as the wing is used to pull open the hatch. is there any other possibilities?????
he suggests using polyeurethane to hold the wing to the hatch surface, but we both agreed that it may need more strengthening than this. however i cannot stand the site of those wings i see held on with rivets all the way around them. my friend suggested using a few screws ocassionally around the perimeter of the wing (the ones with the end caps to conseal their appearance. is there any other possibilties???????
from all pictures i have seen, these style wings have no drainage watsoever! the hatch will then tend to rust out as the wing will affectively be a bird bath. is it therefore better (or possible?) not seal the perimeter entirely and allow drainage through hatch surface and wings underside surface?

advice would be much appreciated
aaron (zenki 83 levin)