This is the method I used and can be adapted for many types of faceplates (i.e. the piece of material that surrounds your stereo to fill in any gaps). This really applies when no dash kit / adapter is available for your make of car.
For a picture example of this technique applied, go here: http://www.avic411.c...php?p=6806#6806
If you have additional techniques or ideas please add them.
NOTE: this is not intended to serve as a means to mount your stereo. This is intended to help you finish the job with a clean look.
Metra ABS Blank Gridplate (12" / 12") - Has a grooved grid on the back to make cutting straight lines very easy
Rust-Oleum Textured Paint for Plastic (Black) or alternate color / texture
Razor Blade Knife / Utility Knife
Very Fine-toothed saw / Japanese Dovetail saw (optional for faster cutting of the ABS plastic. Available at most home improvement stores)
Medium and Fine Sandpaper sheets
Orbital Sander with medium and fine sanding disks
Mini Blowtorch (Only needed if you need to create a curved faceplate. Available at most home improvement stores)
If you need a flat faceplate:
1. Take horizontal and vertical measurements of the opening in your dash where your factory radio is currently installed (it may be easier if you have already removed your factory radio).
2. Lay the Metra ABS Blank Gridplate face down on a hard surface (use an old towel to keep it from sliding around).
3. Using the utility knife or Japanese Dovetail saw, cut the Metra ABS Blank Gridplate to size (or just slightly LARGER than the opening in your dash)
4. Position the newly cut piece in the dash using the sandpaper to sand it down to a perfect fit.
5. Measure the exact width and height of the part of your new stereo that will extend from the dash beyond the faceplate.
6. Using the utility knife or Japanese Dovetail saw, cut out the opening (or just slightly SMALLER than the size of your new stereo). The grid on the back of the ABS blank makes it easy to cut to any shape.
7. Position the newly cut piece around your new stereo using the sandpaper to sand it to a perfect fit.
8. If the Metra ABS Blank Gridplate finish does not already match your dash color or you want it to be a flatter black or other color, use the orbital sander to sand the glossy texture from the front of your new faceplate (again using an old towel to keep it from sliding around).
9. After you have sanded the faceplate, wash it in tap water to rinse off any dust and dry it thoroughly with a paper towel.
10. Using the Rust-Oleum Textured Paint for Plastic, paint the front of your new faceplate following the directions on the spray can. This will add a lightly textured finish to your faceplate (if your dash has a smooth finish, you can use non-textured paint for an exact match).
11. In addition to the snug fit around your stereo that will hold your face plate in place, you can use small strips of the leftover ABS material to build up the backside edges of the faceplate to enable it to 'seat' firmly against the area beside the radio. Use the super glue to join the pieces where necessary. 'Clips' can also be easily fashioned out of the ABS material if needed. NEVER permanently fasten the faceplate to the dash.
If you need a curved faceplate:
Follow the directions above but use a flexible sewing measuring tape to measure over the curves of your dash to get the width and length of the dash opening.
After you have cut the ABS plastic to size and sanded it (before painting), carefully use the mini blowtorch to lightly heat the ABS plastic where necessary to enable you to bend it to match the contour of your dash.
Large round PVC pipes / tubes, a drinking glass or other round surfaces can be used to achieve a good curve. The key is to be patient and test your technique on scrap pieces before doing your final bending work. Once cooled, the ABS plastic will keep its curve for the life of the car.
Finish your faceplate by washing it in cool water and painting it to match your dash color / texture.
I hope this is helpful to the do-it-yourself people out there.