Checked the cam cover today, which was fine & had no leaks. Took the cover off to make sure.
Got the car nice & hot, idling for around 20 minutes & couldn't see any drips. In hindsight, i should of left the oil filter instead of tightening it, that way i could of got a good look if it was actually dripping. But as i originally said, when i first looked at the filter it was getting ready to drip. Hopefully this was the cause.
I also notice that further up the underside, there seems to be signs of oil. I'm wondering if at speed, the oil could make it's way there from the front? Like how water travels along you arm if you hold it horizontally.
New oil/filter ordered anyway so shall see how it goes.
On a positive note, whilst poking around the engine i found the cause of the annoying rattle which is a cracked shield. The metal that covers the front headers.
I also squirted myself in the eye with the washer.