What should I do to atone for blocking the path of two cars and forgetting to move my car from their way, and the resulting inconvenience to their owners, knowing that I do not know the owners of the two cars to ask for their forgiveness?

The questioner is legally excused if they caused annoyance or harm due to forgetfulness, as forgetfulness is among the things for which accountability has been lifted from the Ummah of Muhammad (peace be upon him). Allah the Almighty said: "Our Lord, do not impose blame upon us if we have forgotten or erred," and Allah said: "I have done so." The Prophet (peace be upon him) said: "Indeed, Allah has forgiven my Ummah for error, forgetfulness, and what they are forced to do." There is no blame on the questioner. It is recommended to supplicate for the owners of the damaged cars and to increase in good deeds, because good deeds erase bad deeds.