I'm curious about your perception around the depreciation on a brand new BMW over five years?
Your going from a car that has lost the vast majority of it's depreciation, right back to the top of the depreciation ladder....
All the costs you've cited are still going to be present, apart from a lower petrol bill, but have you seen BMW's servicing prices??
Also, if you've got enough cash to buy a brand new BMW outright, why you worrying about the zeds costs??