2019 Honda Insight EX
I think these guys did a good job showing off how the Insight does on steep mountains. Have your speakers turned up and you can hear the droning.
Edit: I also want to add that the mics could be picking up more noise than one would hear while driving in the cabin. I notice this with my dashcam where it would pick up more road noise than I would hear while driving(It could be the active noise control system at work).