Bass is 250hz and below, mids are 500hz to 2khz, highs are 4khz and above. Your present graph shows mids and bass set essentially flat except for a slight boost at 32 and 2k. Highs are maximum boost.
Response of the normal automobile speaker will begin to decrease at 60hz and be down significantly at 32hz, so the slight boost at 32hz from the amp means the 'heard' 32hz tone would be in the negative range.
Most listeners would boost the bass, leave the mids flat, and slightly boost the highs.