Characters can become vehicle crew members, while still being independently editable entities. The available vehicle roles are:

When you hover over a vehicle, a panel with all the crew icons will be shown next to the vehicle's icon.

The additional icon is shown on the crew members which are rendered in the scene (i.e., the car driver, but not a tank driver who is hidden inside).

To move a character into a vehicle, drag it onto the vehicle's icon or model. If there is no space left, the character will only be moved to the vehicle's position.

To move the character out, drag its icon out again.

You will be notified when attempting to drag a character in an enemy vehicle. While it is possible, it can cause problems in the scenario.