[sperry]

RTFRB:

Originally Posted by 2007 Solo Rule Book

Video cameras, if installed, must be securely mounted to withstand loads from driving maneuvers. The camera may be installed either inside or on the outside of the car. In either case, its mounting method and position must not interfere with driving or pose an additional hazard to driver, passenger, or course workers.

Originally Posted by 2007 GCR

9.3.12. CAMERA MOUNTS
The mounts for video / photographic cameras shall be of a safe and secure
design. The body of the camera (recording unit) shall be secured at a
minimum of two (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
come in contact with driver. These rules of attachment do not apply
to the remote lens of “lipstick” cameras, which weighs approximately 2
oz. The remote lens of these cameras may be secured with items such
as cable ties and racer’s tape. Helmet mounted cameras are prohibited
regardless of size, weight, or location of camera on the helmet.

You have to meet the solo rules. I'd recommend meeting the GCR so there's no question things are legal.