Oil leak valve covers 99 2.8L V6 30V

[Ed Rodriguez]

 Here's my story.  Popped the hood to find oil leaking onto the exhaust of my companion's 99 A6 Quattro. Felt along the lower bottom edge at the rear of engine - found fresh oil. Tried to tighted nuts to no avail, oil still leaking at valve covers

Thought I'd be the hero and replace the gaskets myself.  Remove the valve cover to find a rubberized gasket with a ribbed surface.

Picked up a new one, cleaned the surfaces - ready to install, hmmmm  No gasket sealer used-can't locate a torque spec or sequence.  Now I'm stuck - Need some help here!! 

Does anyone out there have the torque spec and sequence?  

Is there any place else where the oil could be leaking from since its hard to poke your head down there by the firewall.


TIA, 
ED
Port Orchard WA
' 84 5K
' 85 5KT
' 90 200T