A comprehensive insurance policy should technically cover damages caused to your car in a wash shop. If you weren’t at fault in the incident (like, for instance, you didn’t scratch your car against a pole or a wall when you drove it in), then your insurance company is likely to be able to subrogate the car wash and have your deductible returned. This would be the easiest solution, because you don’t have to sue the car wash yourself to have your car repaired. If you don’t have comprehensive insurance, then you cannot file a claim on your liability or collision policy.
It is advisable for car wash operators to purchase a general liability insurance policy to protect themselves against damage caused by negligent employees or malfunctioning equipment. Such a policy can pay for eventual claims from customers who got injured or whose cars were damaged while being in the car wash shop and can cover settlements from any personal lawsuits filed against them. But not all car shop owners buy such insurance.
Be warned that a lot of car wash venues come with disclaimers. They deny all liability for eventual damages that occur to your vehicle when you use their service, as well as for any injuries you or your passengers may sustain while your car is being washed. Be warned that some of these disclaimers may have no legal grounds and you can easily have them voided in court. Even if they are in line with the law, there may still be reasons to sue like, for instance, if you manage to prove that they were operating with negligence. Consult with your lawyer for a solution if your car was damaged in a shop that had such a disclaimer.
All in all, if you have proper insurance then file a claim and get over it. Even if you will get a surcharge and won’t have your deductible returned, the lawyer fees and the time wasted in court are hardly worth the hassle. Such lawsuits can last for a couple of months and, in the end, you will have spent more money than the few hundred dollars for the deductible.