Next, smooth the piece over with Duraglas and sand out the rough spots. Be sure to let the piece cure completely before removing it from the vehicle in order to prevent warping. Once you've decided where everything will go, and made sure the equipment actually will fit, start cutting the existing factory bezel. Use a Dremel tool to cut the trim a little larger than the bezel that came with the radio. This makes the head unit look stock. Do the same with the HVAC bezel and relocate the buttons.
Now fill in the gaps with Rage Gold body filler. Smooth it out to the edges of the bezel. Remove the equipment again so it won't be scratched during the sanding process. Start with 40-grit to knock down the high spots and finish it off with 80 grit. It's important that there are no imperfections since they'll definitely show up during the primer and paint stages.
The best way to securely mount the driver is to create a ring. This way the speaker can mount from the back. Cut a ring from MDF and round over the inside edge to eliminate unattractive 90-degree angles. Superglue the ring in place. We'll use acrylic to mount the tweeter that comes with this. Cut out the desired shape and bend it to get an interesting angle.
Glue the tweeter pod in the desired location and Duraglas it in place. Then, superglue the entire tweeter mount to the center channel piece. To match the rest of the interior panels, take a piece of the dash to a paint shop so that the paint could be dye-matched. It only takes a few coats.
Install the center channel panel to the dash to make sure that the tweeter piece is lined up and straight. Then, mold it to the center piece with body filler (we don't need the strength of reinforced body filler, which is harder to sand anyway).
After giving all three pieces a final sanding, it's time for primer. The Slick Sand variety can be built up and sanded very easily. Before reinstalling the panels, stick the soft side of Velcro to the edges to prevent the panels from rubbing against the dash and damaging each other. The finished result will look completely integrated - much better than the mishmash of colors and dash kits that were in place before!