Equalizer ...

[Mukhalled]

Turn up the volume and your engine will go faster because it sounds louder. ;D

hehehe exactly  ;D

It effects the Cd-player. Where should i use capacitors ... in the power supply, I'm using 14,4V from the car-lighter.!  ???

 

[audioguru2]

It might be alternator whine. Connect a 1000uF/35V capacitor with very short leads to where the +14.4V and 0V are connected on the amplifier's circuit board.
The stereo cable from the output of the CD player to the amplifier's inputs should be shielded audio cable, not an extension cord for earphones.