Believe it or not, the same thing happened to me this Sat. too. I was going to do my oil for the first time myself and when I got under the car, it was bad news right away. I could see that the crush washer under the drain plug was dished around the plug from overtightening. And after trying to get the plug out, all I did was round the head off. The only thing I didn't try was using an impact on it, but it is pretty tight to get anything but an air ratchet in, which probably wouldn't have enough torque anyway. I gave up before I completely destroyed it, and took it to the dealer Monday. I had seen some oil on the bottom of the pan, and apparently the washer was actually slightly cracked from being so tight. I asked that they not tighten it so much, so hopefully next time I can get the plug out myself. And they put in a new plug, which I got charged for, but for $3.49 I didn't bother with complianing. But I can't imagine anyone who would think you have to tighten a drain plug that much. And what did it do to the aluminum oil pan on my V70XC? Idiots.