I made one myself out of aluminium. Here is what I used
- 5 threaded rods (M10), about 22cm
- a hollow rod that fitted loosely around the threaded rods, which I cut into 20pieces about 5 cm each,
- 3 aluminum strips about 5cm long and as wide as I needed the grill to be.
I first drilled 5 equidistant holes in the middle of the strips, then ran threaded rods using the small hollows as spacers. I then used a grinder carefully following the shape of the car, just concentrating on one side of the car first, and only shaving off the top and bottom strip. I used a dremel to get it exactly right, on just one half.
This is important because the curvature of the grill has to contour with the body so each strip is not the same.
The I took the whole thing apart again and traced the curved part of half of each strip on a piece of paper and used it as a template to shape the second half. Then I took the two shaped pieces (top and bottom strips) and just made the middle strip go halfway.
It was an interesting exercise but I can honestly say that the result was better than a 355 grille.