The thing that caught my eye was the comment that what you saved on fuel with a diesel you lost on servicing and parts.
My Brabus does 30 mpg on average and just did 18,000 miles before the service light came on (if you ignore the 6,000 mile extra oil changes, which cost less than a tank of fuel to carry out). Over 18,000 miles, at 30 mpg we are talking 600 gallons or 2,700 litrs or approx £4,000.
The diesel (hot) hatch we have in the house hold (Seat Lean Cupa FR150) requires a service every 10,000 miles and even when driven hard, still achieves 50 mpg. The parts to service this car cost less than the parts to service the Brabus, (even more so if you include the OEM brake pads that each had at their last service). At 50 mpg, over 18,000 miles, you would use 360 gallons or 1,600 litrs of fuel, which would cost just under £2,300.
You can do quite a few extra services for £1,700.
Its not all bad for the Brabus though. Its faster and more nimble and much more fun to drive (even though the Cupra is not slow). Also, as mentioned in another thread, the Cupra has suffered several reliability issues over the last 12 months, which have used up most, but not all, of its cost advantage.