[Graham]

Why not assign points to the fastest lap time on rally stages, similar to circuit points determined by your finishing order.  10 for 1st (or a # depending on the # of cars in the event or class) down to 1 for participating.

I think on this kind of proxy with different track types, and measuring techniques it always difficult to get a unified approach to fixing a standard method. As long as the measurement is accurate and truly represents the comparative performance of the cars I tend to like to leave it up to the hosts to decide on what works best for them.
So I feel is best to apply the points to the finishing positions of the cars as measured by the host.

But I am very grateful for your input and open to any suggestions which are offered.