oil leak

[s2_bo]

I seam to be leaking some oil on my D2 S8, its leaving a few little puddles every time its parked, i have had the under tray off and found the sump is very wet.
All the bolts are tight though so its not leaking there.
Seams to be coming from near the front of the engine on the driver side.
I cant really see where its coming from as there is far to much stuff in the way..
Could it be the oil pump seal?

Its prob losing about 1l every 500 miles..
I'm fairly new to these engines so any advice would be much appreciated.

Thanks.
Bo