I just ordered a set and I know most people have been using self tapping bolts/screws but I couldn't help but think a toggle or molly with a little blue lock tight would be a more secure option.
Meaning I didn't take apart the fender to see behind it. It is not exposed but suppose you could remove the lining to access it. What's the objective to ensure the screws hold? The self tapers have been holding great.
That's the point of the molly or the toggle, you don't have to thread it on from the inside. You put it through from the front and it expands when tightened giving you a metal nut inside to anchor to.
But yes, my main concern is ensuring the screws hold over time. But if everyone is having great success with the self tappers I should be good. Thanks for the help.