She sounded early teen on one of the videos, am I right? You may suggest her to treat the car like a person - and you wouldn't want to record a person from behind and miles away, right? An example should also work (at this age they absorb everything, especially when you don't tell them to

) - you may show her some nice videos, both RC and real cars, and just complement the composition.
On the other hand, you'll need to learn to let her know "where the car will be", and then stick to it. Or in other words: give her a chance to work out a better angle and take the position beforehand, and make sure it pays off ("I went ahead and it made a better video") rather than... well, anything else ("I tried but it didn't work, or made things worse - so why bother").
And the the thing that always worked best for me: just swap the roles
.But first, please, show her this

:
Good luck!