I recently replaced the front door speakers in the wagon, and thought I would share some pictures and comments.

The driver door had no speaker, and the passenger side had an aftermarket 4 inch. I decide to replace both with 4 inch speakers because I knew they would fit, however with some modifications.

After pulling the door panel and peeling back the plastic, you are left with this:



First, I traced the opening with paper, and transferred that to a 3/8 inch birch plywood scrap. I cut it to fit, and tapered the edges so the piece fit nicely in the recessed opening.

Next, the mounting holes are 4 inches apart and take #8 sheet metal screws very nicely. I cut a 4 inch square from paper, and used that to mark the holes on the plywood. I drilled oversized holes so I had some wiggle room. The screws I used were 1 inch with over-sized heads. Here is what it looks like mounted in the hole:



The plywood fits flush in the recess and screw heads protrude ever so slightly. Not a problem.

Next, I mounted the door panel and traced the speaker cut out onto the plywood, and removed the door panel:



This is NOT the hold you will cut in the plywood.

Next, I removed the plywood, and used the speaker-specific cutout template to trace the opening I wanted to cut, centered on the door panel circle I already traced. The door panel opening seemed to be correct for a 4 inch speaker, so the two circles were very close to one another. I cut the hole along with a notch for the speaker wire and remounted:



I test fit the speaker with the window down, then reassembled the door, and then mounted the speaker to the plywood.



That's all. The other passenger side was a breeze as I used the first as a template to easily create the second plywood backer.

The speakers are mounted solidly to the plywood which is solidly mounted to the metal in the door and help keep the door panel secure as well.

Comments/questions welcome.

Thanks.