[Kevan]

I wonder if any clubs will hold specific races for these cars...  

We have a class called 'Small Sports/Saloons' - the proviso is 9mm max width tyres and 54mm max across the tyre walls...
...this Volvo is comfortably within both of those dimensions

It's never going to compete with our normal Saloons, 10mm wide tyres and 64mm across the tyre walls so maybe fighting it out with Mini's and AC Cobras is where this will be most competitive.