it also could be a brushed aluminum trim part.
partnumber 51169150236
Looks similar but is way more expensive... 294 eur on hubauer...
but here is one used for 150 usd:
https://www.ebay.com/itm/265778869268
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2009 35i DCT Havana brown with ivory white interior. Mods: Cobb stage 1+FMIC, Wagner EVO1 FMIC, BMS DCI, KW V3 suspension, M3 front control arms, Hardrace RTAB, Michelin Pilot Sport 4S tires.