gearbox leak

OK. After reading the latest posts on Mike's site

http://99mpg.com/blog/finally-i-have-an-electric-car-chevy-bolt/

I decided it was time to take a look under ours. I don't have a service pit, or a hoist, but have done plenty of work with a pair of ramps over the years. I spent an hour crawling around under the Bolt with a small LED flashlight. Had a ball, and learned a lot. I didn't end up needing to pull the 28 small bolts holding the belly pan on. There are eight holes in total that you can run a finger up in, and around, and you can actually see the top side of the pan, and the bottom of the drivetrain, from the passenger side wheel well area. Also, the steel tubes where the o-rings are located, are visible, and you can run your fingers over them from under the hood. I am happy to say everything is bone dry. While I was down there, I checked out the brakes, suspension, sway bar, and rack and pinion steering. The bottom of the car is closed up from the front air dam, all the way to the backend of the battery pack. Not sure why they didn't make any attempt to close off the two feet under the cargo area, unless the air is so slowed down by then that it wouldn't make much difference. I checked out the electric parking brake units while I was back there. Interesting that both front and rear bumpers are massive aluminum extrusions, under the plastic covers.

What I had assumed was the AC, or some other pump noise, turns out to be the pedestrian noise maker that runs any time the car is in gear, up to 15 mph. More bizarre, with the car in Park, with no accessories on, if you pop the hood, the AC condenser runs, and you can feel it vibrate slightly under your hand. It goes off when you close the hood. Whatever could that be for?