-
Fair. I guess you could do a quick sensitivity to see how much it would have to lose in value to equal the monthly cost of the Golf.
How long would you plan to hold the M5 for? Could you run a second calc looking at the cost over that period, rather than over an initial 24 month period?
The maths looks right, but instinctively the conclusion looks wrong. As others have said, the M5 would probably end up costing you more in servicing. Plus there is a reasonable probability (maybe ~25%) of something very expensive going wrong on the M5.
They're going up in value at the moment, that's a guess but one that's relatively safe I'd say.