Fabia mk1 amp and speaker issue

Hi guys, I'm going to post this in the ICE forum as we'll but I have an issue with my amp and speakers where you can hear the engine noise and steering through the speakers, I have tried using a ground loop isolator and all that seems to do is make my music quieter, it slightly recuses the engine noise but make the music quieter, I also have used ferrite on my head unit wires to try to get rid of the problem as well, I have also moved the grounding point to various points on the rear of the car but still no joy, any one have any ideas?