With the companies I use for the classic policies, all cars over 20 years old (if not XR/RS) are able to go on classic policies. If XR/RS, it is normally from 10-15 years old to be eligible.

Yours should be fine. Who do you use for the S1?

Ours are with Peter D. James and it only costs an extra £20 to add another classic to the policy with unlimited mileage and agreed value.

You could technically get both covered on identical cover for almost the same price as one. Might be worth a look. Only thing with them is that you need to be 30 or over to be eligible.