My experience with molding in fiberglass to steel is a bad one.
The factory was probably right on this one.
Either all steel or attach with a visble seam.
I think that you will find that the paint will crack at the molding point somewhere.
I believe that the GT5 flare is bonded to the fender. Many adhesives now have strength test numbers greater then the materials they are bonding too.
From what I have used even something like the PL construction adhesives would work. Once they cure they will never come apart and certainly are 10 fold stronger then the fiberglass is.
Dont't the fiberglass GT5 flares have internal flanges that would accept a rivet? I have seen some that do but I don't know what is a factory part and an aftermarket for sure.
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