Thanks for the info. I'll say that I haven't inspected it in great detail, but the entire circumference of the pan seems to be wet. I have removed both the front and rear plastic belly pans in preparation for this and some other work. Where are the level sensors located (front, rear, driver, passenger)? if it is a leak at the sensor(s) how are they repaired (gasket, sealer, new sensor)? I don't even have my torx socket set yet, I ordered one online. I haven't had occasion to use them and I've owned the car since late '03. I'll continue to search the site, as it has a lot of great info. Thanks again for the insight.
It's entirely possible the sensor (passenger side, you'll see the connector going to it) was earlier replaced and they didn't use proper sealant or, just as likely, didn't do proper prep so the sealant didn't seal.
If it is all the way around at the gasket point, then you're right, there's probably not much point in investigating further for the source. There is a common leak point at the front of the engine, but that wouldn't explain a leak line horizontal to the engine and at the gasket point, particularly at the rear of the pan.
I would still suggest cleaning it up as best you can before you start disassembly, but after draining it. that way you'll have a clean surface on the upper pan so you can tape some plastic over the opening and prevent dust, hair, etc. from floating up in there while you're cleaning up the lower pan. Have some clean, lint-free rags to stuff up around the inside edges of the upper pan while you're cleaning the old sealant off, too.
Good luck. Hopefully you have someplace relatively cool you can work on it.