Actually inspired by this video (or at least partially) I put AN couplings between both feed and return to an oil cooler that I was planning to mount for a long time, so I can drain the oil from the cooler/thermostat/oil lines at the lowest point when draining the oil, ensuring to getting all the old oil out during a change.
This video convinced me whether this is important or not for a car you cherish.
During the build in june this year:
