[Cliff Beer]

I would tend to agree - always safety wire the spinners. This is particularly true where anti-seeze has been used to prevent galling of the alloy threads and the coefficient of friction is therefore less (making it easier for the spinner to unwind for the same torque setting). The aviation industry uses safety wiring extensively due to the vibration intensive environment and the high cost of failure (same as on a GT40 wheel). As to correct rotation IMHO it's not that significant which direction the spinner is rotated as, for example, a rear wheel experiences both/opposite rotational loads under braking and acceleration - the purpose of the spinner is simply to a) not unwind, b) so as to not allow the wheel to wobble and come off the pins and alignment provided by the hub facing. Just my $.02. Incidentally, I have had a wheel just about come off a car at speed - a 1964 E-type drophead while in college - but it was because the splines were shot allowing the wheel to rotate on the hub and work the spinner loose.