I think this was a spare. For some reason it has some corrosion behind the clear coat or the outer lip. I'll try to get some pics of that.

Thanks for looking

The HAL9000 says

The product is an OEM factory spare BMW E39 525i 530i BBS RS740 style 17x8 2-piece wheel rim, featuring a silver aluminum construction with a conical seat bolt pattern. It includes a wheel center cap and has an offset of 20mm. The rim is designed for high performance vehicles and is compatible with BMW models. Made in Germany by BBS, this two-piece wheel rim is a genuine BMW part with the manufacturer part number 36111094377. It is a high-quality, durable wheel option for car enthusiasts looking for a reliable and stylish rim for their vehicle.