Polishing the aluminum grille is quite simple. It does require that you purchase some sort of Aluminum Polish such as that pictured below.  Simply wipe the polish on with a rag or a paper towel.  Apply liberally. It will get in the holes, just keep working it so that the entire front surface is covered with the polish.

Once the grille is sufficiently covered, buff the polish off with a rotary tool.  If needed put a sanding pad on your drill motor and wrap it with a rag.  The hi-speed will do all of the work.  I have done it by hand, but it won't look as good.  The rag or buffing pad will turn gray, this is an indicator that the processis working. 

You will then want to do a final clean-up with some sort of cleaner.  Windex or 409 will work great to remove the polish and aluminum debris that is left on the surface of the grille.  For an even higher shine, repeat the hole process.  The Mazda Miata MazdaSpeed shown on our website was polished only once using a cordless drill motor and a shop towel wrapped around a sanding disc.