This will make it a bit unrealistic, but it is 100% working.

All you have to do is to use Sit in Nearest Car animation for the passengers, and Enter Nearest Car for the driver. Sit in Nearest Car simply teleport the actor into the car, while Enter Nearest Car... you know what happens. This way driver will always be the last to enter the car, allowing all passenger to enter first. Even if driver drives off before passenger gets on the vehicle, the passenger still has a chance of being teleported into the moving car.

Or, you can just use Sit in Nearest Car for all actors, so they all teleport into the car at the same time. Though Enter Nearest Car makes it much more realistic, good for cut scenes!

Hope this helped!