^ Well if Valeo REALLY does make the OE part, then a new Valeo is OEM...and a rebuilt Valeo is a rebuilt OEM....and a core rebuilt by unknown is an aftermarket.

One comment to the OP- ECS tuning buys OE parts from a BMW dealership.

Lots of Internet vendors source OE parts from various dealers.

Plus lots of BMW dealers run internet storefronts.

But to my knowledge there is NO vendor for OE parts that is not also a BMW dealership.