I was informed about 2 options:
1) either pay about $1000 for them to find it or
2) do pretty much the same that PrinceAli recommended, clean the engine, drive it & then look for the leak but i believe there were 3 places that the leak could be originating.
Here's another thought, mine leak is barely weeping so maybe a drop or 2 per day driven, and i have the oil changed every 3-4 months so it's not a huge loss. My car is a 1998 ES 300 so, given that it's a decade old, it's a fact that it will eventually leak just because seals will not last forever.