It is true that an inert object in the wind will not get colder than the still-air ambient temperature. (Neglecting the miniscule heating by friction of the air)
However,the vehicle was not an inert object. There was a source of heat within it, that is, the girl's metabolism.
The girl's body heat ultimately has to be transferred to the ambient air around the vehicle. This transfer would be slower if there were no wind than in a wind. Heat tranfer,
in general, depends on the square of the velocity of the transferring medium as well as other factors such as density of the medium, etc.
That's why the concept of wind chill factor was developed for humans in the first place.
Thus, technically, it would feel colder to the girl with an outside wind than without. Whether this would be significant depends on the actual numbers involved, such as clothing insulation, etc.
So while Hawkmoon is right in terms of the semantic impact of using wind chill factors for dramatic purposes, it is true that the girl would feel colder in the vehicle with an outside wind than in calm conditions since the rate of heat transfer from her body to the outside world would
technically be greater due to the outside wind. Whether it would be dangerous or even noticeable or not.... depends.
In other words, the vehicle could be looked at as if it were another layer of clothing.
Terry
(1) For general reference, the rate of heat generated by a human is
approximately the same as a burning candle.
(2) This link shows the relation between temp, wind velocity, and wind chill factor for humans for an area near me:
https://forecast.weather.gov/MapClick.php?lat=39.7836&lon=-105.1675&unit=0&lg=english&FcstType=graphicalIt will only show graphs for the time you click on it. Note they don't even bother calculating a difference above about 47°F. This "factor" is based on type and amount of clothing for a given temperature and is, to the strictly technical mind, kinda flakey.
It kinda represents an approximate engineering solution for a genuinely scientific, precise physical phenomenon.