Hey Deicustoms,
I actually spent a good amount of time and couldnt figure out the slope feature to work. I got fed up and just reverted back to the pink/black wire. Everything works great except for the slope feature. I'm sure one day i'll figure it out.
as for the reverse... i tapped to a brown wire on the drivers side A-pillar. much easier to access. the wire comes from the Mirror which un-dims the rear view mirror when reverse is selected. this triggers the signal for the rear cam to go on.
I'm not sure what you're talking about when you say brain. the D1 is one huge unit that goes where the stock radio went. I didnt mount anything other then the on-star module which I just tucked away in the BIG whole on the center console..
I hope this helps you out when installing your unit. Shot me a PM if you have trouble with any wires other then the slop... as I still havent figured this out myself.
cheers,