I just got my AVIC-D2 and have been told all kinds of crap about installing it, so now my brain is overheating with what is and what isn't necessary. I have the parts needed (mounting kit for my Civic and the wiring harness), but I'm unsure when it comes to the wiring what is absolutely necessary. Do I HAVE to wire it to the reverse light/sensor, speed sensor, etc. or are these just optional for add-ons (i.e., back-up camera)? Otherwise is this not a whole lot more difficult than installing a regular head unit (just twice the size)? Please give me some feedback about this before my head explodes and I never get the chance to use it