What to do if a car dealership released my credit info to someone else?

What they did was negligent, so that part of having a case is fulfilled. Unfortunately, there must also be some damage, or economic loss or injury, before you can sue--the legal system only provides compensation for actual losses, not simply because something happened which *could* cause injury or loss. Unless and until you suffer from loss due to the improper release of your credit information--which is hopefully highly unlikely, since your daughter received it--there is nothing to sue for.