That photo appears to be of the Throttle body/valve...but to the right, near your hand, appears to be a hose that I'd wager is the breather that goes to one bank of your v6.
find a similar hose/tube connected to the opposite bank, and follow it to the intake manifold. Pull that hose off where it is connected to the intake manifold, cap/plug that port, and then T-connect this hose to the one in the photo.
Once you have followed this procedure, you will have completed what is likely the most important pre-groove modification: the PCV cap/re-route.
If I recall correctly, BMWs had what was basically a gauge in the instrument cluster that measured "efficiency" but was really a manifold vacuum gauge. If yours does, it should start behaving differently - staying on the high efficiency end of the scale for longer, and moving to it sooner.
drive the car, taking note of how it runs and your fuel consumption. You should see a decrease in fuel consumption, but just a slight one. but you should also feel a slightly smoother and possibly more powerful (slightly!) engine/car.