The scheme is underwritten by NIG, part of the Royal Bank of Scotland group.
Douglas Robertson, SMTA chief executive, said: “In the past few days we have had a franchised dealer join the SMTA solely to access the scheme and I am convinced that this is only the start.
“It is, without doubt, the most competitive insurance scheme have seen for some time.”
Giles Insurance Brokers has been the SMTA’s recommended brokers for five years and already over 20% of the membership use them for insurance purposes.
Robertson added: “I think this figure will see a considerable increase over the next twelve months as members seek quotes from Giles to renew their insurance.”