as loudr' mentions the a/s factory store has them (well they had 2 in june)
they are aluminum, but not alclad and have sorta a brushed finish.
there is also a stainless steel version that some dealers stock (i have one of them)
they look nearly identical but obviously aren't.
because the vent FLAP is heavier than the plastic version,
it needs 2b PROPPED open 2 function well OR the vent FAN needs to be robust or run on HIGH
here's a couple of threads with PICTURES of the stainless version many of us now have....
its possible 'timeless' the custom shop near you also has a metal version...