Finally something recorded...
This sound happens before any action from me to start the car etc.
My Nest captured the sound (though not very well). The clip has the sound followed by me groaning about not getting it recorded on my iphone. My wife reminded me about the nest cam.
This is an occasional but frequent sound. This sound is loud enough that it masks the normal power up sounds.
Sound at 1 second time stamp
https://www.dropbox.com/s/n2e1nvavb7...Noise.mp4?dl=0
I've tried the brake pedal during a noise event but no sensation.