JimD thanks for the pics. Yes, I know about these types of valves. I guess I am old school... I prefer just the OE bolt and copper washer. But use what suits you & your car best.
Ianc, not to beat an old horse dead... but... BMW says the car needs seven quarts so thats what I put back in. When I drian the oil... I always measure how much comes out. On both of my oil changes, seven quarts came out. So... seven quarts went back in!
My Electro-dipstick always reads the same. Full. Even after several hours of driving at Warp speeds on the autobahn.