Hi,Could someone please help me installing the Infinity basslink active subwoofer to my Audi a3 8p 2004 model.I have pretty standard Half amplified Audi symphony 2 stereo in my car.front two speaker are run by headunit and rear two speaker and the original sub is run by factory amplifier.Could any one please guide me how to get the feed for inifity basslink as audi symphony doesnât have any pre amp output.Any help or advice will be much appreciated.Regards Jav