Pesky oil leaks - 2003 3.0 w/56k miles

[e39_touring]

I bought this '03 3.0 with only 55k miles, and it had a lot of oil leaks.

I've done the OFHG (sourced from BMW) and VCG as well as put in a new PS high pressure hose and return hose (from the reservoir to the PS pump).

That's taken care of the major leaks, but I'm still getting oil drops forming underneath on both sides of the motor, and I can't figure out where. It seems to accumulate at the bottom of the front diff and the passenger side axle support as well as in back at the bellhousing. (I'll try to snap pictures when I have it in the air next)

It's definitely not gear oil. Seems like engine oil and not PS fluid (it's thin but not red). I'm thinking the only culprits left could be the oil pan gasket and/or rear main seal (yikes). The trouble is the fan and airflow is blowing the oil all over the place making it real hard to tell where it originated. Any tips on narrowing it down? Anyone ever tried the UV dye?

p.s. - the VANOS hose off the oil filter housing is dry, and there is no pooling in the engine block webbing below the OFH. So, I think that one's OK now although it is in the vicinity of where I see oil accumulating most (front left of motor).