how to use bondo

If your talking about eliminating the dash pad and filling the holes in the frame its best done by welding sheetmetal patches into the frame, but to do this you'll have to really protect the glass or pull the dash. Another option would be to rivet some tin under the holes in the dash and then smooth with bondo. I dont think tape would be strong enough to support filler because it has to withstand vibration and lots of heat.