Must someone who causes an accident to a borrowed car pay compensation for its diminished value after repair, or is its repair sufficient? And in the event of a claim for its value, what is the accepted basis for appraising the car?

The borrower guarantees the item he borrowed if he is negligent with it or exceeds the permitted use, or if the borrowed item is damaged, even if there was no transgression or negligence. However, he does not guarantee the reduction [in value or quantity] that occurs due to the purpose for which it was borrowed.