Plenty of Minis here in several forms of motorsport in this Castrol film featuring seven different forms of motor racing from 1972; Drag Racing, Autotest, Hill Climb, Autocross, Circuit Racing, Rallypoint, Rallying:- https://www.bpvideolibrary.com/record/725
I watched this film on the BP archive and was going to post it up, but then found Martin had done so back in January.
It is an excellent film showing all types of grass roots competition, with a great piece from Harewood. It shows how much the area has been landscaped to ensure the safety of spectators. And seeing the Jag engined Mini Van in action at Santa Pod was a great. Well worth a watch.