By the Bais Hora'ah
Someone double-parked next to my car, and although I was careful as I was pulling out, I scratched his car as well as my own.
Q: Am I obligated to pay for scratching the other car, and if so, how much?
A: There is a difference whether you scratched a car that was parked legally (bireshus) or one that was double-parked illegally (shelo bireshus). The question of your liability hinges on this issue. If you scratched a car that was legally parked, you are certainly liable for the damage. The amount that you would have to pay is the repair cost. This assumes, however, that normally people would repair this damage. In a circumstance in which people would not repair the damage — for example, the car is very old or already badly damaged — instead of paying repair costs, you would be liable to pay for the loss of value that resulted from the damage, which may be nominal, depending upon the circumstances (see Chazon Ish, B.K. 6:3).
If you scratched a car that was double-parked despite your efforts to avoid damaging the car, you are exempt from paying for the damage. You may not, however, seek reimbursement for the damage to your car from the person who parked illegally.
The Gemara (B.K. 27b) teaches that one who trips and breaks a container that was left in the street is exempt from paying the owner for it. The rationale is that people are not expected to be extra careful while they are in motion. Obviously, that does not apply here, since a car is a large object that one is expected to see, and a driver is certainly expected to watch his driving.
However, a different principle can be inferred from that discussion. Halacha rules ‘avid inish dina l’nafshai’, a person may act unilaterally to enforce his rights. For instance, if someone fills a street with containers, making it impossible to use the street, it is permissible for you to break those barrels directly in order to use the street, and you are exempt from paying for the damaged containers. You are not required to exert yourself to stack containers placed by someone else or move them out of the way when they were placed there illegally (Tosafos, B.K., 28a, d.h. meshaber).
If, however, the one who broke the containers was damaged by some of the shards of the broken objects, the owner of the containers is exempt, since the “damager” brought this damage upon himself. In the event that the container owner left a path wide enough for people (or cars) to pass, one who damages the containers is liable since it was not necessary to damage the containers, despite the fact that the container owner acted improperly by placing them in the street (C.M. 412:2).
Consequently, if the person double-parked, leaving you without sufficient space to get out, you must attempt to carefully drive through the space that is open, but if you drove in a careful and acceptable fashion and still scratched his car, you are not liable.