you'd wanna use metal when covering up a huge hole.

you are filling up two tiny holes. fiberglassing is the method of choice on shaving emblems and antenna's.

you do know they drill into sheet metal sometimes when they pull huge dents.

do you think they go back and weld up the tiny little holes? nope, they just use bondo.

and dawrenn, you are right you can use just a little bondo.

but when shaving windshield washer squirters and antenna's. you'll need to fiberglass to fix up the dents.

you also have to understand what causes bondo to crack is water getting to the bondo.

so having a layer of fiberglass underneath is gonna make cracks less likely.

there are plenty of ways to do one thing.