From under the car, behind the engine/transaxel, look up, past the exhaust pipe. You'll see two drainpipe-funny-lookin'-things, one at a bit left of center and the other a foot or so left of center (as viewed with your feet sticking out from under the front of the car). They're about 1 1/4" diameter, 6" long and have a 90 degree bend at the bottom. Here's a pic.
The drains themselves are about 1/2" diameter and they have end pieces that truncate in a "squashed" configuration that could be best described as "lips". Here's a pic. They are fairly tough to get to. The "lips" need to be parted and cleaned well; I think the actual cause of the clog is that they tend to stick together. You can expect a "dirty shower" in the process of getting them unclogged. After the cleaning, you have to re-insert the external protective tubes. Point the hinged flaps toward the back of the car (toward the center is OK too).