Far as I am aware, aluminum is ONLY in the S models (not a fan of aluminum and that's why I didn't want an S).
It's likely that whomever had the car before you wrapped the trim pieces in 3M Aluminum.
There is a thread in here with all sorts of wraps done on the trim pieces including white and black aluminum, carbon fibre, and I think it's Mr Luv who did a dip on his trim with the best looking wood trim I've seen anywhere.
If it is wrapped with a 3M or similar product, you can remove it by heating it gently with a hair dryer and peeling it slowly - it will NOT leave glue or marks behind - it will just show the wood that is underneath it. If it's actual aluminum pieces, then the last owner must have bought them from an Infiniti parts shop.
I left my wood trim alone, but I added carbon fiber wrap to the muiti-switch and the console to cover the original material that matched the dash:

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