There is a company called Rural Insurance which has an appropriately named "Car and Van Policy". You can only access their quotes through a broker so I would suggest you find one nearest you. That said, it would only be possible to insure with them if you are a rurally based business so if your in, say, London, you'd have no luck.
I'd recommend any Giles broker - they are up and down the country and much much better than Swinton!