This is what I meant/implied. Air will eventually slow the car down...
Except when it doesn't ... for instance if there is a tailwind.
The larger point remains: I strongly recommend that you break
the habit of assuming this, and break the habit of using any such
figure of speech.
You have got nothing to gain and much to lose by talking about
the "force to keep the car moving".
In the example that began this discussion, drag was not mentioned,
but the "force to keep the car moving" was mentioned ... which
raises multiple objections. For one thing, it is an inconsistent
set of approximations.
In the introductory physics course, when discussing the forces on
a turning car, the traditional approach would be to ignore both
thrust and drag.
If you prefer a /consistent/ discussion of thrust and drag, that's
fine, but you really want to keep it consistent.
The Aristotelian idea that "a body in motion tends to come to rest"
is a widespread and pernicious misconception. It suggests that the
physics of "coming to rest" does not need to be explained. This
sets physics back 400 years. It should be avoided like the plague.
Don't talk that way. Don't think that way.
The first law of motion says that a body in motion tends to remain
in motion.
Galileo is called the father of modern physics, and indeed the
father of modern science ... for good reason.