I'm leaking a little oil from the area by where the transmission meets the engine. But it's leaking from OUTSIDE the plate that covers the flywheel. At first I suspected the oil-pan gasket where it dips like a U, but a friend said it's likely the rear main seal. Any comments on this...does the rear main seal interface with the oil pan ? I thought a rear seal would effect clutch performance, but my clutch is fine.

 

Sounds like the rear main seal.