eh....fuel cap wasn't on properly.
The gasket around the fuel opening is bad, so fuel must have splashed up while I was turning and then trickled down into the trunk (not sure why the drain wouldn't dispose of the excess, but it works fine, I poored a little water into overflow drain and came pouring out at the proper spot.)

Anyway I fixed the cap and dried up all of the fuel, then went for a fifteen minute drive, making sure to take all of the turns a little hard. Got home and checked it and nothing is leaking. Yay.

I'm a moron.

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1982 240D.
My name is Michael, and I am an 18 year old binge-drinkin', cigar-smokin', novel-writin', all around unsavory and unnattractive guy. I tell long-winded stories, and I only shave once a week, although I've had to do it every day since I was 16.