I left insurance out of the list of pure investment requirements for that reason.
There's no doubt that you generally lose money just by owning a car, which is why they are rarely good investments (unless you have a rare Ferrari or such). However, as those costs are inevitable for any car, and the primary objective is just to minimise loss from depreciation, it doesn't seem worth acknowledging them.
Basically, it's not a case of whether to get another car, but which car to get, and for that, the only important factor is de/appreciation.