Few days ago I was doing cap, rotor, wires, plugs, other stuff on my 300SE. Had the radiator out to make the job easier. After all the work was done (but before we replaced the radiator), I started the car up to test it out. Figured that the thermostat was pretty much closed, not much coolant would get out in the five seconds I had the car running.
Forgot about the ATF lines to the radiator. ATF everywhere. Wondered why my friend had a bad look on his face after I revved it a few times.
Also, last time I changed the oil, I didn't double check to make sure the old oil filter's gasket was removed. So I had two gaskets there. Backed out of the driveway, only to notice my neighbor yelling something at me. Got out of car and saw this:
About a gallon or so of Castrol Syntec on my driveway. Not good.