Oil Leak

Hi all, I have an oil leak on my p38 V8 Range Rover. I cant find where its coming from but it is running down the passenger side chassis leg and dripping onto the exhaust resulting in smoke. Not good.
I have taken a few pics for you to look at and hopefully help me diagnose thanks again...
First one is the air con pipes that run behind Evaps unit. Not sure where that loose pipe goes but it runs across the bulkhead and down behind the back of the engine to the gearbox maybe?
Next is the Aircon pipes that run down the side of the wing.

And the last one shows the bottom of the evaps unit..

Any help will be appreciated thanks...

Anyone got any suggestions. I have checked the auto trans dipstick that's fine.

rocker cover gasket or valley gasket,it wont be engine to gearbox if the rear oilseal has gone the oil will come out of the hole at the bottom of the bellhousing