3rd Generation Optima (2011 - 2015)
So I turn off my car while the radio is still on. Volume level is around 3 to 5. When I turn my car on later, the volume sounds like it is jacked up to 15+ and it's blaring loudly..but when I turn the knob slightly to lower down the volume, it says I'm still at the lower volume level (3 to 5)...