A week after I got the Malibu, I lost the keys. I knew pretty much where I lost them - 300 miles away, at a truck stop in Missouri. I didn't feel like driving over to get them, so I pulled the driver's door apart, removed the lock, and took it to a locksmith, who charged me $10 to make a new key.

While the door was apart, I figured I'd install some speakers in the doors, since the Malibu's dash had provision for only one, right in the middle. This turned out to be one of those Projects From Hell, that took six months of a few hours here and a few hours there.

Driver's door, panels off. The forward square hole is to get access to the regulator. The door panel itself is highly sculpted, so you can't just put speakers anywhere you want.
Skipping six months ahead, here's the panel. I wanted a stock look, and I didn't want to chop the door panels up. A little measuring showed 4x10 speakers would work. That turned out to be the first problem - 4x10s used to be popular, but now they're oddballs. I just wanted "a radio" instead of a killer sound system, so any damned speaker would do... but even then, it took a while to locate some speakers locally.
Sort of swapping from side to side as we work... I've used tin snips to enlarge the holes in the doors for speaker clearance.
The edges of the holes got deburred with the burr knife and Dremel, cleaned with solvent, and painted so they wouldn't rust.
The door sheet metal was highly sculpted, so the speakers wouldn't sit flush. I cut some .090" aluminum to make a speaker mounting panel.
The panels looked like this to start off. The notch and tang were an idea that didn't work out...
Even the aluminum panels weren't enough to provide a solid mount for the speakers. The tops were unsupported, the way the door sheet metal was shaped. I cut some 3/8" plywood filler strips to support the panels. The bizarre shape results from clearing the door at the top and the speaker at the bottom, while extending far enough out to bolt to something solid.
Countersunk bolts hold the braces to the doors. There are nut plates inside the door; I made them myself. Heavy coat of paint is to prevent moisture damage.
The speaker, speaker panel, and panel support. 3/16" foam tape should prevent speaker rattles.
Speaker assembled to panel. This is how the speaker mounts to the door, as an assembly. The plywood part stays with the door. More adhesive foam to prevent rattles.
Ready to install...
And here we are! There's a high density plastic flap in the door behind the speaker, so rain can't get to the speaker if it rains with the window down.
The stock tar-paper moisture barrier goes back on...
4x10 speakers were hard to find. 4x10 speaker grilles turned out to be impossible. I finally found a set in the junkyard. Most G-bodies with the 4x10 factory speakers simply had holes punched in the cardboard parcel shelves. But Pontiacs (at least, some Pontiacs) had metal grilles, which just happened to be the right size to fit the Malibu doors. Plus they're kick- resistant... while the door panels were off, they got thoroughly cleaned, dead plastic scratched off with a soft wire brush, and repainted with the proper "camel tan" vinyl color.
Finished! Hallelujah! Six freaking months!