Stratus 4 has a hiss while using the AUX connection

I just had a Stratus 4 installed and I'm using the AUX connection but for some reason, the sound quality is not good at all. It sounds like the Stratus is turned way down and my radio is turned all the way up. It doesn't sound like feedback since this radio is hard wired to power in my car.

My iPod sounded much better than this and I could understand some hiss using a FM transmitter but not the AUX. I didn't expect CD quality sound but this is just disappointing.

I checked the volume on the Status and it's set to max. If I turn my radio way down I don't hear it but I can barely hear the music. Stations like CNN or other talk stations the hiss is more predominant or noticeable. The signal is showing all three bars so I don't think it's my antenna.

Is there something I can buy or check to see what might be causing this? I will try a another line from the dock to my aux connection to see if it's the cable. The installer ran the cables behind the radio and out of sight. I hope it's the cable.

Any ideas?
Thanks!