Hello,
I just installed the auxiliary plug for the mini cooper, it was increidbly easy and just popped right in, but today I noticed theres no sound coming from the passenger side speakers. Its not the speakers because they work with the radio and cds just not on aux. should I unplug and replug it in or what else? Thanks!

 

Unplug/replug is one thing to try, but also make sure that your cable is stereo, not mono. Check by looking at the plug. I posted this a while back:

 

So if its a mono plug then it only plays from one speaker and not two? Is that the only difference?

 

A mono cable should produce the same sound from both speakers, it should not cause no sound on one side.

I suspect that the problem is most likely either the cable is not properly connected, it's a faulty cable, or that the Aux Input needs to be checked right up to the head unit. It's possible one of the wires came loose from the connector.

 

A mono cable into stereo jacks produces sound only on the left side.

Look at the diagrams of the plugs. The right side becomes grounded.

 

Oops, you're right. Never mind.

I have seen mono-to-stereo wires that do achieve same audio on both channels though, and that's probably why I was confused.