Now it's pretty clear why progress was erratic for so many participants on the Monte Carlo Historique rally. Just look at these conditions:
Peter Barker and Willy Cave plow through very slushy conditions on their way from St Etienne to Gap in their ex-Works Morris Mini Cooper.
A 911 goes off -another victim of "Porsche pendulum effect".
A Citroen Maserati SM gets out of shape, blocks the road and causes a traffic jam (I bet that crew was popular!).
A venerable Citroen Light 15 gets a helping hand from spectators.
Rear engined Alpine Renaults thrived in these conditions (BTW, just look at the negative camber on rear wheels).
A Fiat Abarth 124 storms along despite the treacherous conditions.
A tiny Fiat 500 maintains good traction unlike the macho Austin Healey 3000.
A Lancia Fulvia HF 1600 struggles for grip. Note to co-driver: Dude, your car is frontwheel drive and I think it would be better if you sat on the bonnet...!
The mid-engine weight distribution of the Porsche-VW 914s gave them a huge advantage.
The MkII Innocenti Mini of Laloge and Borremans placed 38th overall -the highest of all the Coopers. I would say from this picture that they are using 13" diameter wheels; 12" at minimum. It's easier to get snow tyres for these larger diameters but as far as I know only the original 10" wheels are homologated and thus legal.