I think I've mentioned this before, but I'd love to see an option that would work like "install alarm" (along with the economics of buying groceries). After every twelve community trips (including driving the kids to school) six trips to work, four downtown or equally distant trips (Uni or a downtown lot sim going to a home neighborhood, for example) or any combination thereof it would be necessary to go "fill 'er up!" No animations necessary. And just like an empty refrigerator, the car doesn't work without gas. To prevent the option of simply swapping out cars, each new car could have just enough fuel to go to the pump, and nowhere else.
If you swap out cars, though, you *ALREADY* end up paying, probably more, for the fuel.