Here's my take on running costs.....
Although I have no idea how much I could sell the car for, I'm pretty sure it has now depreciated as much as possible. So, that is one "running cost" I won't have to suffer. Mine is a 2.0, so tax isn't as much as others: £325 at last renewal (how much for a 3.0?). But, taking in to account the saved depreciation, it ain't too bad. My insurance cost £200 for the last year. I think that in order to save on running costs, I'd have to invest time and money in buying something else. Fuel economy is in the 30s mpg and I'm doing about 4k miles a year commuting. So all-in-all, I'm quite content with the situation.
If the car was purely for fun / hobby, I'd be more inclined to go for a tax exempt vehicle.