Well I de-threaded the oil pan drain plug. Local Indy shop put in an insert, but that's not working so I have to get a new oil pan. Ouch. I've been changing the oil in my cars, including BMW's for 20 years. That's the first time this has happened. Evidently, the metal on the E46 M3 oil pan is light, but soft. How do I keep this from happening again. Can't imagine taking the car in just to have the oil changed.