Very grateful for all the figures and input.
I've come to the realisation that I can probably afford to maintain an S8, but not to put fuel in it!
After budgeting for everything else including my Audi A3 I'd only have enough realistically to pay for 4000 miles worth of fuel per year. That's based on 19.2 mpg, though if I drop to 15mpg, then it's 3000 miles. Gorgeous cars but not worth the outlay in my case with so few miles
I still want one despite it being ruinous