So therein lay the challenge.
A challenge which generally meant kids were the prime contestants because of their equally modest size and nimbleness.
I can't recall how many would on average squeeze into the little cars but the figure was startling ... easily more than a dozen.
And they had it all planned perfectly.
Quite often you'd spot the "coordinator" standing there with a clipboard steering each individual Mini stuffer into position.
They'd pile on top of each other and when it was all done and dusted and they slowly untangled themselves to get out the ones on the bottom of the mass clearly showed signs of minor compression.
They probably don't do it very much these days because there aren't too many early Minis around.
Wouldn't be the same seeing how many people you could cram into a Holden Kingswood.
You probably wouldn't be able to find that many volunteers.
Generally the average car is designed to take four, maybe five people.
There are the larger people movers which can take the leftovers from a packed Holden Kingswood but generally it's four or five.
And in most cases the more modest-sized hatchbacks of recent times come equipped with push-down rear seats.
Which effectively means you can stuff as much as you can into them.
I have seen all manner of furniture, fittings and flotsam being carried in the backs of cars, and am often as amused as I am in admiration of how they managed to get it all in there.
But that's the challenge you see, and I too enjoy a challenge.
Of sorts.
I also enjoy a spot of physical work.
Of sorts.
And I also like seeing how much stuff I can stuff into the confines of my compact little 14-year-old Nissan hatchback.
By virtue of its fold-down rear seats it has become my version of the Holden Kingswood ... utility.
Trimmed trees and bushes and shrubs and great fadges of cut grass and other landscape-smothering stuff become my contestants in the challenging game of "how much stuff can I stuff into Nissy today?"
Two packed fadges of clippings and grass and leaves is pretty average, but there is always scope to push the boundaries.
For there is always room beside them, on top of them and yep, the front seat's unoccupied.
Last autumn I set the standard with so much stuff pushed and packed into the thing one of the blokes out at the recycling spot said "I have to get a photo of that" and out came the cellphone.
For when the load was sent over the side the mountain of old greenery it created was quite remarkable.
There were a couple of chaps shovelling stuff out of a ute further along and they were shaking their heads and smiling — one delivering a thumbs-up.
So it came to pass that the autumn of 2019 emerged and after several weeks of our trimming, sweeping, mowing and clipping there was a substantial new mountain of green waste to be dispatched.
Now if cars had minds and souls old Nissy would have groaned and quietly muttered "oh crikey ... here we go again".
Like the clipboard wielding coordinators of long-past Mini filling adventures, I worked to a plan of what went where and in what order, for not only did it have to all fit in but it had to be placed in such a way that it would not be too difficult to unpack at the other end.
It was a mission which resulted in another seasonal cargo of stunning size which drew a few glances at the green waste spread.
But I miscalculated the gross tonnage ... well, kilos really.
The fadges were heavy as they had been well compacted so yep, the shoulder pangs and back twinges experienced while loading were amplified during the unloading later.
There is always a price to pay for pursuing a new record but hey, the autumn of 2020 is far, far away so I'll be right by then.
Whether the poor old Nissy will be is anyone's guess.