Toyota Avalon Subwoofer Enclosure - Tricks Of The Trade

The bottom corner of the trunk originally had a plastic storage container, so there was a gap in this area. Cardboard works great to fill these areas, so we taped a small piece over the hole.

Good aluminum foil is key to almost any fiberglass project, and this heavy-duty Costco food-grade foil works great.

Foil is applied over the tape and cardboard, giving an additional layer of protection between the car and the sticky fiberglass resin. 3M Super 77 spray glue is used to attach the foil tightly to the surface. Plastic drop cloth was also taped in place to protect the surrounding areas.

Fiberglass mat and resin are applied to the entire surface to further stiffen and shape it.

Five layers of fiberglass completely cover the area. Again allow at least six hours of cure time before removing the panel.

Now it's time to remove the panel. These things are often difficult to get out but plastic wedges (available at plastic and fiberglass supply stores) work great to help pry the piece out of the trunk.

Trim the edges of the fiberglass shell and place it back in the car. Test fitting revealed that the front edge of the fiberglass shell needed to be extended to fit the large subwoofer, so a cardboard template was cut with scissors to accomplish this.

Cut an MDF panel with a jigsaw following the cardboard template. Notice the notch added to the edge with a router rabbeting bit-this makes things much easier in the final step of the build process.

Apply more fiberglass resin over the MDF, creating the completed subwoofer enclosure base. Next month, we'll finish up the project.