@223nut
If anyone has got their attention on the vehicle, other than a random passer by or a car thief scoping it out, it is not unattended. FAL does not qualify you to attend to a vehicle, so one assumes that can be done by anyone.
But is your partner allowed to have the vehicle keys without a FAL? Now we are getting complicated, but at least it would be fun to see an additional firearms transport verse getting added to this song:
https://www.youtube.com/watch?v=aZMbTFNp4wI