In reply to owlart:
We've had a similar issue with changes at work recently. Essentially we're now expected to carry work items in our own cars, and work from a different "office" and the company don't consider it to be an issue, as I'm not using my car for commercial use...
But as I and many of my colleagues have said, if an accident were to happen and I had any equipment in the car which suggested I was using my car for work, then the insurance company may well refuse to pay out, citing breach of contract.
Anyway, brought this up with the insurance company due to a renewal recently, and I think it cost me £4 extra for the year to change my policy to Business Use included.
I shouldn't have to pay for it, but it's definitely better than any possible hassle later on!