I was just trying to have fun
the sums weren't the point of it either, but the priorities of choosing. It took quite a while to decide even these fake sums to make some strategy out of it.
I guess one could go on research and calculate right amounts for designing+building cars, buying/leasing used cars, paying entry fees, logistics, travelling, personell costs, testing, fuel, tires, equipment, spares, catering, marketing, public relations, salaries and all that crap, and for every single possible category variation there is, but who would do that for some random forum game?