I've just reviewed the rules on this.
https://www.zone8.org/assets/docs/2019/2019Z8Rules.pdfThe spare tire, tools and jack may be removed and must be removed if they are
not securely mounted. Any device (cameras, lap timers, gps loggers, etc.)
mounted inside the car must be firmly attached to a solid point on the interior.
Interior suction cup mounts are allowed only if additionally secured with
adhesive such as silicone or RTV. Digital cameras or other devices mounted
outside the car must be mechanically attached to the car; if suction cup mounts
are used on exterior devices, the device must be securely tethered to a solid point
on the car (bumper, side view mirror etc.) to prevent putting other drivers or
corner workers at risk.
I have a suction cup RAM mount that I tether to my instrument binnacle with beefy zip ties.