I have that same leak and found a 2min video on youtube under
( Oil leak bmw 745i E66, 545i E60 Front Cover N62 Engine ) going to work on mine right now.



Oil Leak BMW 745Li E66, 545i E60 Front Cover N62 Engine

 

This is what they found. Along with the leak from the valve cover gaskets.. they found a bad crank case valve.

 

I have a 525i that has had issues with a slight oil leak in the winter. I took it back in January of 2011 to try to get addressed, my shop ended up changing a number of things including the valve cover gaskets. I thought it was fixed but it continued where I would smell oil on hard acceleration thru my AC. BTW my repair for that including routine maintenacne was around $900 with labor. There were probably 12 parts that got replaced for the repair including maintenance.

Fast forward to the last 2 weeks and the oil is starting to leak much worse now. I took it into the shop yesterday and heres what they found in my case. My oil pain gasket has a major leak, almost 1/3 a quart I'm losing PER month. They are going to need to replace the entire oil pan and gasket. My transmission is ALSO leaking, so the cover and gasket are getting replaced. My valve cover gaskets were replaced but still appear to be leaking oil. The shop told me at the milage I'm at, 116k the valve cover can warp slightly so putting a gasket will have it continue to leak. So I'm having the valve cover replaced as well. Its almost $1900 for the job for parts and labor. I was in shock when the car was on the lift at the amount of oil that has spilled everywhere. The damn front end removal for accessing the oil pan to replace is almost a 9 hour job. This car gets damn expensive out of warranty.