In the book Racing and All That by Stirling Moss and Mike Hailwood, published in 1980, Stirling writes about his early experiences with saloon car racing. The first race he mentions is a race at Pukekohe in 1979 with Denny Hulme, racing a 1.6 litre VW Golf GTI. He writes about the fact that slicks were banned helped him make up his mind to race at the event. They finished 50 seconds behind the winner after blowing a front tyre and then having to change both front wheels late in the race. He says he thoroughly enjoyed the experience and resolved to fix a regular drive for 1980.
He writes about the earlier 1980 races in the Audi 80 GLE that seems to be fraught with problems, persistent throttle cable breakages and clutch failures. He certainly wasn't enamored by the driving standards in the BSCC series and complains about being chopped by larger engined overtaking cars and then them getting in his way in the corners, a general lack of race ethics with much pushing and shoving than he was used to. The change to slicks and front wheel drive meant he had to change his driving technique but, at the time of writing he was looking forward to the 1981 season.
I remember Stirling doing demonstration laps in, I believe, a borrowed Maserati at Shannonville, Canada at a VARAC meeting in the mid 80s, where I attended as a vintage bike racer when we were invited as a support class at the event.