People claim it's Behr, but I've heard they've only just recently gotten into the market with them a year ago. Maybe they just started to produce generic, non-BMW versions of it. Every site I've been to claims the updated expansion tank is made by Behr.
Either way, that's the one I got. Looked and felt absolutely identical to the old one, fit perfectly.
SEE SIG, DOGE IT ALL
My opinion is the opposite of your opinion, even if you change your opinion to my opinion.