I don't get it either.
Really late to the thread but I wanted to respond. The car is an ideal place for a video. You can control the conditions...no kid yelling or anyone for that matter. No phone..door bell..timer...interruptions...and can totalling focus on your video and thoughts. No room with clutter or distraction. Sound contained. I see why they pick the car. I often think in the car.
Jumping in here, have been exhausted, with all the festivities.
On them talking in their car, maybe they do not want to be tracked to in their home
Have read where people can track right where picture is taken.
FWIW