It would be nice if the oil drain valve had a magnet attached to it somehow. The selling point of the drain valve to preserve the life of the threads on the oil pan. It's one thing if you're doing your own oil changes and know what you're doing. If you leave it to someone else, you introduce the risk of having the threads stripped which usually results in having to replace your oil pan which is quite costly.
2011 E90 M3 ZCP/AW/Ohlins R&T