Does it only happen when you turn the steering wheel? It sounds kind of like the electric power steering pump to me.
My EcoDiesel, whenever I'm going slow speeds coming to a stop, as I press the brake I hear a bit of a chirp myself. I've removed my brake pads and rotors on all four wheels to make sure there's no rocks in there. At this point I'm pretty certain the chirp that I'm hearing is coming from the brake pedal itself, I'm thinking I might need to throw some silicon gel on there and lube it up a little bit.I wish I had selective hearing with this annoying chirp
Here's another thought for you, my wife Subaru Forester has this annoying whistling sound, somewhat similar sounding to that original video. Not quite as pronounced but definitely an annoying whistle all the same. Took me a while to figure it out but you could hear it while it was idling or at slow speeds like you were saying. What it was is the fan on the front of the engine for whatever reason makes this weird squeaking sound when it's running. Which would kind of make sense that you would hear that when you're hitting the gas or idling, at slower speeds the fans going to be working more to bring air into the engine bay. Whereas when you're at higher speeds you're not going to hear it as much because there's enough wind moving through the engine bay that the fan doesn't need to run as much.
