i think its just a case of producing a stencil. you could easily create the logo on your computer using a vector graphic tool like Adobe Illustrator and take it to a vinyl company to make the template and then just spray over it onto the mesh grill.
I might be completely wrong though, but i have seen other logos and designs on front grilles done in a similar fashion.
I might be completely wrong though, but i have seen other logos and designs on front grilles done in a similar fashion.