drain hole oil filter housing?
 

on the oil filter housing beside the mounting face for the oil filter there is a small hole which I believe to be a drain hole to take away any oil spilt when removing the filter.

is it a drain? and where does it go?

I ask this because whenever I do an oil change I am super careful not to have any oil spill onto the front aluminum undertray when I take out the drain plug. but every time I change the oil I have to clean up oil from the topside of the undertray after driving it for a couple of hundred km's. Once it is cleaned up I don't get any more oil there until the next change.

I pre-fill my filters before installing them so I spill a small amount of oil - I am assuming that it goes down this drain hole and gets left on the top of the undertray.

I have googled but can't see an answer to this.

IN terms of where is goes, just look directly below the hole. It serves an alternative purpose, however. When you install the body of the Subaru XT/WRX oil to water oil cooler there is a small tab on the bottom mating surface that fits in the hole and serves to locate the cooler body with the hoses in the correct place.

OK - thanks for that info, will have a much closer look in the morning. Cheers!

It's pretty common for the FA20 engine to have oil leaks in various places.

I don't believe there is any thru-drain on the filter cup.