I believe they are metal, if I'm not mistaken. How can I know for sure?

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2003 Volkswagen Jetta Wolfsburg Edition, "Tiffany," - Black/Black Cloth - 75K miles, Jetta #6; my faithful, turbocharged, BBS-adorned sled

SOLD 3/08 1981 Mercedes Benz 300D, "Elise" - Astral Silver/Black M.B. Tex - 217K miles - I miss her everyday; the best-built car I've owned