So. I installed my flares today.
Aluminum 1/4x20 rivnuts (24 of them)
Rubber GM welting (25ft roll)
Ace Hardwire 1/4 x20 machine screws, finishing washers, and, rubber washers.
Rivnut installer tool (lol)
Tapped up the flare exactly where i wanted it, then drilled a 1/4 hole threw the flare, hitting the medal behind it. It will leave a mark in the medal so you know exactly where to drill.
Then you pull it off and start drilling (step up your size drill bits) you want to have a 13/32h hole end the end.
Used my handy rivnut tool. This is why i used alu. Rivnuts. Mine all came out prefect.
Install rubber welting, as you see fit. Not rocket surgery.
Bolt it all up.