i installed My z1 2 month ago, but the audio shop didnt not install the SCOSCHE car stereo 2/4 channel adjustable output converter for me, i have been told its not necessary. is it necessary to install that thing? cuz I am using the factory speakers

 

common, people, please help~~

 

so u installed the aftermarket HU without the scosche already? Is there any scratching sound or distortions? If none then why would u need to install it?

 

not really..