I've tried looking online, but I can't find a description and the images are too zoomed-in to tell exactly where the AC drain hose is. Another problem is that the hose might vary between generations.
Underneath the car, where is the BMW e46 AC drain hose located?
EDIT: The exact make is 2005 330ci. The images are from searching 'e46 AC drain location' or other similar variants including '2005', '05', 'bmw', etc.
Because there are significantly more 6 cylinder engines in the E46 generation 3-series, I will make the assumption yours is a six cylinder variant. From experience, there isn't a huge number of differences between core components on things like AC between the 4-cylinder engines and 6-cylinder ones, but it's more likely things like the radiator and engine componentry change with the increase in cylinders.
Usually the condensation hose (AC Drain hose) is situated as in the picture below.
Note the little hose part no.9 in the image is your drain hose. I found an image from Bimmerfest of one up close and personal.
I hope this all helps you track it down easier!
Since no pictures exist on the internet (that can be found) on where exactly the drain comes out at, hopefully this picture will help describe how you can help yourself figure this out:
I found this video of a guy removing the AC box from an e46 330i. In the above circled area is the drain location on the AC box itself. This would correlate to the center of the car, directly over the front half of the transmission. You will have to get under the car (make sure it is safely placed on jack stands) and look from the back of the car forward at the end of the transmission, between the transmission tunnel (floor of the car) and the top of the transmission. If you can squeeze yourself in there right, you should be able to see all the way forward enough to see where the drain comes down through the floor and to where it goes. It should be about the only thing which is in this position (remember: center forward portion of the transmission). Through looking at all of the other BMW photos, I can tell you that BMW has placed the drain on the left side, the right side, on both sides, and has just let it drain on top of the transmission. Your guess is as good as mine. What I can tell you is, it will be a soft rubber hose. Depending on the angles which it will bet to actually get to the AC box, it may not be easy to clear any blockage.
