Zeke,
I wished the PIE MPSS4 worked that way. I hate having my radio shut off when the empeg is playing. I'm really a ricer at heart because I want to see both units' pretty colors in my dash.

mem,
I'll scan them and post them. Yeah, I don't know how they mess with the power either. I thought my installer had messed it up, but I confirmed that it is the correct behavior with PIE's tech support.

Boxer,
The "source switching relay" from PIE cost like $15 I think. And the Sony XA39 has sold on EBay for $5 (if you can find it). So, the PIE is the hands down winner for me since there are no more Sonys and I can't make my own.