Standard U.K. car models are also classified into numbered insurance groups, which will affect the premium (group 1 being the cheapest - I think the highest is about group 18, but I'm not certain).
There is also a huge element of "think of a number, double it, multiply by the number of cups of coffee you've had this week, then deduct the number you first thought of." You can't do anything about the price of the road tax or fuel, but insurance quotes can vary widely (wildly, in fact) between different companies for the same car, same driver, and same conditions, so this is where it really pays to shop around, get plenty of quotes, and play the companies off against each other when they ask if you've already had any other quotes.