Before you start cutting holes in doorpanels, consider every alternative. Speakers won't sound their best when pointed at your knees, and they'll be visible to anyone walking past. I once "hid" a multichannel sound system in a pickup by building a shallow overhead console for the mids, flush mounted to the angled panel with mesh over it that matched the appearance of the headliner. I also put 1" dome tweeters in the rear corners of the roof. The owner kept the stock AM radio in the dash and installed a hidden stereo with a wireless remote. Subs and amps can go under/behind the seat, so from outside the truck there is no evidence of a high-dollar system. The best part was that we only had to drill holes, no cutting of the original steel was required.
