i use 'rescuemycar.com'
it costs £40 a year
its personal cover so covers me in any car, and national recovery i.e. - i broke down in durham, which is like 300 miles from home or so, they recovered me the whole way home no problem.
i have used them quite a bit, so well had my moneys worth over the years.
1 term it has, is you have to be at least 1.5 miles away from home, which is fine, as if i was that close id be just walking home or phoning a mate anyway, but if it was a problem, i could just register the policy as another address anyway.