I have the 3 gauge pod with the tweeter. The instructions tell you to put the gauge pod OVER the stock "A" pillar cover. You can do it this way, but then you have to cut large holes to fit the wires through and it does not completeley cover the stock pillar cover.
The thing is, with 3 gauges the pillar is heavy, so heavy it sometimes falls from the top clip. To solve that problem, i put a screw in the top, then painted the head black. Its bareley noticable and the pod is now rock solid. There is no need for a screw on the bottom since it tucks in behind the dash panel so it wont move anyhow.
Since you are putting the screw in the top, the clips serve no purpose, so there is no need to use the stock "A" pillar cover at all. Just mount your gauges, duct tape the wires against the back of the pod so they dont get caught up and slide the bottom of the pod in first, then while holding the top up, drill an 1/8" hole throug the plastic, then into the metal behind it, (you will see what i mean. there are no wires inside the metal, so dont worry, just dont drill too close the windshield) then put a #8 or #10 self tapping screw in and your done. Your pillar will never fall or come loose, no spring clips to worry about, no need for those plastic pegs, no wiring hassle and no grinding of the plastic cover. I tried not using the screw, the pillar clips just cant take the weight. If you need a pic, let me know and ill post it.