Hi Rainmaker, I spent a bit of time this afternoon hunting to get it back, and stumbled across it where it has moved into an App Tray, as I recall it was titled, along with a few apps. I'm not at my PC now but think it was near the bottom of the vertical app bar on the right.
I was also a bit concerned as I run triple monitors which means most cars start with quite a large amount of adjustments so the square mirrors app drive's me crazy with click click click click click click click click click click click click...