It's no use for you, I know, but for others looking at new vehicles google GAP insurance.
I just went to the first link and an MT-07 which is sub £7k you can get, for a payment of £45:
Pays the difference between the Motor Insurers Settlement on the day it is written off, and the invoice price you paid or amount outstanding on finance which ever is the higher.
For a years cover.
For less than 1% if your vehicles cost it seems worth while for peace of mind. 2 years cover takes it up to £56.
Obviously you'd want to look into the reviews of these companies. They might turn out to be as much of a pain to deal with as the rest of the insurers.