The ceretec bottle does suggest that mixture ratio. However, I am of the school of thought that as little as necessary is the better answer. If zero ceretec is ok, it can’t be bad to only add 1/3 bottle if that takes care of the tick.
That looks like it would be the recirculation flap. When it opens and closes, it causes air from outside or inside the car to be “sucked” into the blower.
My wager that I’m willing to bet zero dollars on is a two seater called Mustang cobra. A smaller car with some S650 styling cues to compete with BRZ type cars. Could just be my eyes, but trying to compare profiles of that teaser and current and previous mustangs seems to look like there is no...
As an example, on some BMW models, approaching directly from the front may not work, as there is a blind spot for the system in that direction. Not sure how it works on the Mustang, but maybe something similar happened?
This is supposed to work automatically as you approach the car, without any button presses? If so, perhaps the direction that you approach the vehicle has to do with it.
Doesn’t matter, just has to be inside the car for it to start.
I mean, do what you want - it’s your car. Just wanted to point out out something that may have been overlooked.