Body Filler or Fiberglass
 

What is better to fill the holes left after you pull the trim off the rear and front bumper, body filler or fiberglass.

If you have a mig welder I would put a tack in the holes and grind them flat, if not go with a fiber reinforced filler but you will have to make sure you get a good key to the metal.

Yeah, I would definitely weld them up.

Kalamazoo eh? I work in downtown. Filling those holes with glass would be better but it will still eventually pop and crack. Best option is to weld or get replacement parts without the holes.