My original post seems to have provoked a lot of discussion on the matter.
I still have not decided yet to go down the line of a new 370z. Nothing to do with the road tax. More to do with the amount of money I have to put with my car to get the 370z. I really do not know if it is worth it with the mileage I do in it per annum. I could keep the 350z and buy 3 Dacia Sondero's (That is a joke by the way but it gets you thinking of what else you can get with that sort of money, especially when you add the cost of finance on top of it).