Originally Posted by o2batsea
Obvious solution is to replace plastic inserts with rivnuts and use machine screws to attach the guards.
That sounds like a terrible idea. Ever seen what happens to the sheetmetal when a gaurd that utilizes rivnuts gets ripped off ? It looks like the exit wound of a bullet hole. You don't want your sheetmetal to be the weakest link.
You can probably find those plastic inserts at a local PepBoys or something.