i just got an 04 fx4 build date was 08/04. my rss works with or without the stereo being on and it WILL mute the stereo when it senses something while in reverse.......oh, it is the audiophile setup with the sub and amp and 6cd in dash.....hope this helps.

 

I don't think it is a combo of options I think it is build date. Could it be Lariats? Who knows

But here are my specs just in case:

Lariat 4x4
Audophile
DVD
Captain chairs
Floor shifter
Built in KC
Power Rear Window
Dual Power/Heated seats

Every factory option availble from what I can tell.

I'm just as **** so lets figure it out.

 

I got the plate and hitch plate from a local accessories store, the mustang some how showed up in it when I took the picture.