Baking soda, not baking powder, neutralizes the acid. I would replace anything removable that the acid touched, as it tends to soak in. If it ran down into the storage compartments and got to the metal structure of the car, remove all the trim panels and prepare a large amount of baking soda solution (5 gallon bucket?) and pour it liberally into any areas where the acid might have gone. Allow to sit for a while (after any fizzing stops), then rinse thoroughly with clean water. You may neet to make a drain hole in the main compartment. The two side compartments already have them, with removable rubber plugs.