2011 Prius III Pioneer AVIC-Z110BT PAC-TATO

I just purchased a new 2011 Prius III with the JBL package. Sound system sounds great, but I wanted to use my already owned Pioneer AVIC-Z110BT from my previous car. So I have most of the work done already, but I'm experiencing tons of problems with the PAC-TATO module. It is constantly fading the volume up and down during my entire drive and getting annoying very fast. Anyone else find a real solution to this?

I've seen several other posts about people unhooking the rear output and then it works, or others have posted that they used a line level to rca converter and that fixed the problems -- but I'm not a fan of an ad-hock install -- I like clean and correct.

Also, I hooked up my rear view camera and have everything wired, except I'm having difficulty finding the reverse wire -- anyone have luck with that?

Thanks again for all the help!