Last year took my new-to-me Subaru to the base auto hobby shop for it's first oil change by me, put it up on the lift, drained some dark black fluid, lowered it back down and put the recommended amount of oil in. Started it up and drove it out the garage. Almost immediately it was having a really hard time shifting and would hang in neutral for a few seconds. After about 200 yards I realized the huge fuck up I had done: I'd drained the transmission and doubled up on oil... Carefully pushed it back to the garage and onto a lift. Checked the oil and sure enough, there was WAAAAY too much. Had to call a friend to take me down to Wagner Subaru at 4pm to pick up 5 new quarts of Subie tranny fluid, swing by and grab another 5qts of Mobil 1, and head back to fill up the tranny, drain nearly 10q of half bad, half brand new Mobil 1 out of the engine. Best part was getting to do all this over the course of 3-4 hours in front of a bunch of other guys working on their cars and the staff mechanics at the hobby shop. That was the last time I bothered doing my own car oil changes.