Does the iPhone have a feature to balance sound?

I have the iPhone 5 and recently got a kit that hooks up in my car through a plug in the back of the radio originally meant for a cd changer. However when I play music through it, it seems like the sound (more so the vocals) always seem to be louder on the front passenger side speaker than front driver's side. I know when you listen with headphones on it's nice to have different sounds coming out of the different sides but in the car I'd prefer the sound to be equal in all the speakers. Does anyone know if that's possible through my phone?

Yes. Go to Settings, then to General, then to Accessibility, then to Hearing. It should have a "L" on the left which means left speaker or ear bud, ect. And a "R" which is right speaker or ear bud, ect. Then adjust to your pleasing…