Hey guys....picked up one of the PinGraffix Magnet Speaker Grill Covers from Joe.
Have attached a picture of my Met with it installed. Literally takes less than 10 seconds to install and less than a second to remove. Priced right, easy mod, and looks great. Well done Joe and all the PinGraffix folks.
Here is a link to PinballSuperNova with their review and pictures of installation.