A migrating queen is almost certainly resting or chilling out in the side mirror, the rest of the swarm is just following her and chilling out until she starts to move again or lay eggs, at which point they follow or start building a new nest on the spot.
For those wondering what/why:
A migrating queen is almost certainly resting or chilling out in the side mirror, the rest of the swarm is just following her and chilling out until she starts to move again or lay eggs, at which point they follow or start building a new nest on the spot.
And she will get to wherever she is going faster if someone would just toss her the keys