Not that we do everything the same, but the Secret Car Club of America requires a two points of attachment to the car & camera. I would argue a suction cup violates the "secure" intent.
9.3.12. CAMERA MOUNTS
The mounts for video / photographic cameras shall be of a safe and secure
design. The body of the camera or recording unit that weighs more than
8 oz shall be secured at a minimum of 2 points on different sides of the
camera body, neither of the attachments may be elastic or plastic. If a
tether is used to restrain the camera, the tether length shall be limited so
that the camera can not contact the driver. Helmet mounted cameras are
prohibited regardless of size, weight, or location of camera on the helmet.
You could argue the GoPro is under 8 ounces, but as an open wheel guy, I wouldn't want someone's loose camera bouncing off my head like Massa's spring incident.
tim