You wrote "latches" but I read "hinges" for some reason. On my Challenger hood latch and safety hook, I soaked them in EvapoRust. Then I darkened them in a black oxide solution. Then I coated them with RPM from ECS Automotive. On my Dart hood latches and safety hook I did the same. On the trunk latch and striker, I sent them out to be replated with the rest of the hardware. If you are going to have the latch replated, it's best to disassemble it first. The replaters use acid to clean the parts before plating. The plating only gets on the outside of the part. The inside will remain bare and will rust.