Tim, I think the above is an interesting idea as a race with a difference if enough support could be mustered. I actually thought of something similar myself in a moment of letting my mind wander.
I thought about a race with family pairs, but slightly different. My thought was along the lines of a sort of team race between the younger family members and the older family members. The “Young Guns” versus the “Old Guard” if you like. (Not an NZ style team race I might add, but just a normal UK race).
Points could be added up at the end of the race to see who comes out on top; the more hungry younger drivers or the more level headed older statesmen of the sport……………………………