What are the common oil leak sources on M120?

[chiwanga]

I recently purchased my first MB V12, a 97 s600. 130k miles, extensive service history. It is leaking some oil on my driveway. I'm going to take a look tomorrow but wanted to get a heads up on what are the most common oil leak points, and what's involved in repairing them, e.i is engine removal ever necessary, or do rear main seals fail often. Thank you.