Cheap auto insurance

A new year is coming, and new ways to save money must be thought up... One idea I have been thinking about for a while, is to save on income tax by replacing my company car with a private vehicle.
If I were to do this, it would be essential to keep the running costs low in order to ensure a saving is make over all. I would need to secure some cheap auto insurance and ensure that the vehicle were not one that would need a lot of expensive maintenance in order to make the swap worthwhile.

I need to offset the potential savings (tax) with the potential costs (maintenance, insurance and road tax) to ensure that I will not end up spending even more money...