One of the most visually important parts of kit and custom cars is the grille, since that's the first thing people see. In the 1950s, many custom cars featured grilles with square or rectangular patterns made from flat metal stock, which became known as egg-crate grilles. Many production cars also used similar grilles, including 289 street Cobras, most Ferraris, and the 1965-67 Sting Ray. Custom car builders usually made their own grilles from aluminum bar stock, and they're easy to fab yourself using only a tape measure, a chisel, and a table saw. I made one for my Devin project car, and although the first one was thrown in the scrap bin, I learned enough to not make the same mistakes twice!
Follow along with the photos and captions and your replicar grille could be making a great first impression if you too decide to fabricate an egg-crate grille. | 
Start by measuring your grille opening. Leave some extra room around the edges so the grille bars will disappear behind the edges of the opening. Think about how the grille will be installed and how you intend to mount it. | 
You will need flat aluminum stock, which is available at hardware stores in various widths, thicknesses, and lengths. Pick a width and thickness you like, and then buy a 6 1/2-inch metal cutting disc the same thickness as the aluminum you are using (less than $2) with a 5/8-inch mandrel hole. |
You probably won't need many horizontal bars (I had four) that will need to have slots cut in their forward-facing edges. Clamp them to the sliding miter gauge on the saw, make sure they're square to the face of the saw, and center the saw blade to your center marks. | 
The grinding action will leave some rough metal debris on the edges of the slots. Remove this with a sharp metal chisel, which is less likely to scar the aluminum bars than a file or power tool. | 
Mark the aluminum bar with a fine-point Sharpie pen to indicate length and where the grille's cross-pieces will go on center. You may want to make a cardboard grille first to check how it looks before you commit to metal. |
You will need lots of vertical bars, and they will need slots cut in their rearward-facing edges. Cut to length and then securely tape them together on the ends with good duct tape. Then measure and mark where the horizontal bars will cross them. | 
The newly slotted bars are ready for assembly. Make a final check for the correct height of each slot. | 
Replace the woodcutting blade in your saw with the cutoff wheel and adjust the height to half the width of the bar stock. Mine was 1 inch wide, so I set the blade to 1/2-inch above the table. Make sure the blade is perfectly vertical. |
Once again, set alignment, clamp securely to the sliding miter gauge on the saw, and push the bar stock over the spinning wheel. Make sure the cuts are all the way to the half-width mark and that they are perpendicular to the bottom of the bar. | 
Assemble the grille by pushing the vertical bars over the horizontal bars. You may need to put the grille in a vise to push the parts together, but don't force it too much, as you may have a slot that is not deep enough. |  |
Make a set of brackets to mount your grille. I made a C-shaped piece of aluminum that bolts to the grille on the ends and mounts to the body with buttonhead cap screws. Each grille is different, so some other design might work better for you. | 
Here's the finished grille mounted in Project Devin. It's just what I wanted, and at a price of under $40! You can leave it dull aluminum like I did, polish it out, or paint it any color you like...you can have your egg crate any way you want it! | 
The AC Ace grille had different thicknesses of vertical and horizontal bars. This is more complicated but doable. |
The grille is designed to be held tight against the backside of the grille opening with the horizontal bars pushing the vertical bars against the edge. | 
The Ferrari 500TRC sports a classic egg-crate grille. Ferraris usually had an aluminum surround as well. | 
The Stallion Cobra replicas used egg-crate grilles in both the radiator and oil cooler openings. Note that these have been painted black. |