For this 2014-2018 Mazda 3 (Third Gen.), we did a basic sound system and did a Stage 1 sound treatment package on the doors. Here is what we did.

Products used:

CLD Squares: 15

FD1: 1 yard

Butyl Rope: 8 feet

The first step is to obviously remove the door panel. There is one behind the panel that is behind the door opening handle, and one underneath the rubber mat that is in the arm rest.

Once the door panel is off, this is what you will see. Pretty much all Mazda vehicles will have this thick composite plastic skin that will need to be removed to get to the outer door skin. Dont worry, its a bunch of 10mm bolts and a few 10mm nuts. You will need to remove the window regulator, which you can see sitting behind the door opening handle in the photo below. It is held in with three 10mm bolts. This is where you need to be careful. Behind that regulator is a mechanism that twists off the plastic panel. Once removed from the panel, the insides of that mechanism have only tension holding them in place. If you pull too hard or move it in a funny way, that yellow gear will pop out and you will be in for a rough time. take it from me. (This happened to me on a CX5 a few years back. took a second person and a few hours to get it back together). What you need to do as soon as you remove it, is wrap painters tape around it to prevent the yellow gear from popping out.

Once that plastic panel is removed, there is a ton of room to work. Use butyl rope in between the outer door skin and the crash bars, then apply your CLD.

Once the outer skin is done, move onto the door panel. Here is what you will see once it is removed.

We folded back the OEM fiber mat, and liberally applied CLD Squares to the area around the speaker opening

Once that was done, we applied Butyl Rope to the little nooks and crannies of the door panel to prevent buzzing from panels vibrating against each other. Unfortunately, they are hard to spot in this photo but it was placed near the underside of where the buttons are located, around the door handle, and around the styrofoam piece in the lower right corner

After you re-install the plastic access panel, you can install your CCF. For this car we used our FD1. We didnt find it necessary to add CLD to the plastic access panel since said panel has many curves and is very rigid out of the gate. Applying super tiny pieces of CLD would yield pretty much no benefit. After this, we installed a CCF ring around the speaker and re-installed the door panel.