My spectratone chart shows silver over reds as a pastel color, not really a metallic red. The Spectratone setting is in the same box wher you assign regular edge colors, under the color swatch on the right side selcct the arrow next to "Gerber Standard Foil Palette" and change to Spectratone. If you have transparent red foil try printing that on silver metallic vinyl, that may work.
I have silver, silver medal and red transparent if you want me to test for you. You can PM me the file, but I am out of town - cant print until next week.
Here are my results. The overprint on silver medal - middle one didn't do full overprint for some reason.
Honestly none are really that special, or pop- out. Trans red over silver looks decent.
The true Red medal would look the best if you want the chrome look.