This month we will finish off our project 350Z door panels. I'll go through some basic techniques that will involve routing aluminum, doing bodywork and painting. Check future issues for more how-tos on kick panels and dash construction and more. Send any questions to Zee at techpanel@sourceinterlink.com.
It's time to insert a mounting ring into the fiberglass for our MB Quart speaker. | 
With a jigsaw, cut off the excess material around the rings, leaving 1/8" of material behind. | 
Attach the template using double-sided tape to your second ring. |
Using a rabbet bit, remove enough material so that the speaker sits flush to the top of the ring. | 
Apply Duraglas around the speaker ring, bonding it permanently to your fiberglass insert. | 
To hide the mounting screws of the speaker, I've made a 1/4" aluminum ring that trims around the cone of the speaker. |
Clamp the aluminum to a tabletop. Use a jig saw with a metal carbide blade to cut off the excess material, leaving 1/8" behind. | 
Using a carbide router bit, flush trim the excess of the aluminum off. | 
With the template still attached, use a chamfer bit to give a finished look to the ring. |
Surround the aluminum ring with three layers of masking tape, leaving a perfect gap for additional primer and paint. | 
Apply Duraglas and Rage Gold body fillers around the aluminum ring, molding into the insert. | 
Leaving the ring in place, hand sand the surface with 40-grit sandpaper until the desired shape is revealed. |
Drill and recess bolts into the inserts that will later get filled. | 
Mold the inserts into the factory plastic door panel. | 
Tape off the tops of the inserts and apply Duraglas around them until the desired shape is acquired. |
Now remove the masking tape. With an angle grinder, shape the Duraglas with inserts in place to blend the new shapes into the door. | 
To further blend your new shapes, apply Rage Gold body filler. | 
With guide coat sanded and inserts put back in place, it's clear that the shapes blend perfectly to the factory door panel. |
Polyester primer is applied over the whole door panel to seal all bodywork along with creating a uniform surface. | 
With upholstery complete, it's time to get the fiberglass inserts ready for paint. | 
Apply three medium wet coats of polyester primer. |
While the primer is drying, sand the aluminum ring to prepare for the polishing process. | 
Apply blue compound to the buffing wheel and buff the aluminum until you get a chrome-like finish. | 
Guide coat the primered inserts and block sand with 220-grit sandpaper. |
I've chosen a silver color, so I'll apply three coats of base and three coats of clear. | 
These two shots show a simple but clean door panel that can be accomplished in about three days of work. |  |