I took delivery on a MKIII with a Roush 427SR and the installer told me that the small
oil leak from the front of the bell housing was likely a rear main seal. I was told to drive the car 300 miles and bring it in in which I did. The dealer was authorized to fix this.
Afet 300 miles they pulled the engine and transmission and found a pin hole leak in the rear of the block. They sent the engine back to Roush who sent a replacement. Roush had the engine about 4 days. The rest of the time was trucking back and forth to Michigan.
New engine runs great. I'm completely satisfied.