Just seen on this month's AA survey:

"Under the current car tax system, many petrol, diesel and hybrid models with low CO2 emissions (less than 130g/km in year 1 and less than 100g/km in subsequent years) are zero rated.
From April 2017, only cars with CO2 emissions of 0g/km (pure electric cars) costing less than £40,000 will be zero rated.
For everything else, following a first year rate based on official CO2 emissions, there will be a flat rate of £140/year, or £450/year (years 2 to 6 only) for cars costing £40,000 or more when new."

Don't know what happens if your car is over 6 years old, or if this only applies to new cars.

I was looking at a Citan Deisel and that had zero tax.

From a purely practical perspective whatever they charge I will have to pay it as I can't do without a car .......... but it is unlikely to say the least that I will ever buy a new car costing over £40.000

We thinking of changing our car but it won't be a new one. Will ask questions or search in here later for recommendations