Hey,
I lost 2l of oil in just 2500km, I'm guessing it's due to a leak. Everytime I leave the car overnight, I find an oil stain when I return (about 5-6 drops of oil).
It's under the right side of the engine (slighty middlish).

 

Most common is the Cam Cover rubber gasket/seal.

The engine is tilted to the RH side, and that area of the interior of that cover is oil saturated.

2L in that many miles is not out of the question via that point, but a bigger mess would be evident in my opinion??

 

The X300 is usually pretty oil tight apart from the regular issue of damaged drain plug threads so leaks on the RH side are rare.

Difficult to tell precisely where it's coming from with all that old oil and dirt mixed together.

I'd degrease the engine, run it up to temperature, leave it to stand overnight and then look for the source.

Graham

 

They are also susceptible to an leak from the front right of the head gasket where a high pressure oil pipe is located very close to the edge of the gasket.
You will need to follow above advice and give it a good clean first to determine source.