Following the thread - if somewhat 'off subject'. When was the rule introduced, 'seated within the confines of the car', or words to this effect?
I recall spectating PCT, Stafford & District MC, early 1960's, VW Beetle, footplates on the rear bumper, and grab handles on the roof - with passenger suitably mounted. And incidentally, a characteristic of East African Safari Rally cars of the era, and even entries within the 1968 London-Sydney Marathon. e.g. the ''Works' Hillman Hunters.
From when onwards were trials passengers required to be seated?- One for our distinguished historians.