Is it permissible to seek the assistance of someone who did not witness the incident to give testimony based on what he reviewed from the lawsuit documents, knowing that the difficulty in proving the car's stoppage is the unavailability of witnesses who were present at the incident? And if one were to proceed with that, would this be considered a false testimony?

This issue is one of dispute and contention, and the judgment in it belongs to the Sharia (definition) court. Scholars have differed on the issue of bringing false witnesses for someone who denied a right and found no other way. Among what Ibn al-Qayyim mentioned in "I'lam al-Muwaqqi'in" is that the purpose of a stratagem is to obtain a right or repel falsehood. If the means itself is forbidden, such as bringing false witnesses for a denied right, then the person who does so sins for the means, not the intention. An example of this is when a man denies a divorce, so the woman brings false witnesses to testify to the divorce. Another example is when one has a debt with a person who denies the trust, so the rightful owner denies his debt or vice versa. This person sins for the means. In such a case, the hadith (definition) states: "Return the trust to the one who entrusted you, and do not betray the one who betrayed you."