When using the Multi-Class racing in Free-Play you can end up with cars several classes above the one you are using which means that they can easily lap you. Since in Free-Play the race doesn’t end till the player crosses the line this can lead to situations in which the winning Drivatar has completed the required laps but the player still has laps to complete. What ends up happening in these situations is that the lead Drivatars continue acting as though they are still in the race. This can lead to these cars that have completed the race to cause chaos by crashing into players or other Drivatars.
My latest experience with this had a Drivatar that completed the race 4 laps earlier than I did slamming into my car causing damage. This should never have happened because that car should not have still been on the track multiple laps after it had completed the race.
So cars that have finished the race should either be removed from the track or be ghost cars.