I've lurked on here for years, and a huge thanks, kudos to everyone for asking and answering the questions that I've been using as guidance.
I started my little project almost 3 years ago, and it's sat on the shelf for most of that time for a number of reasons. Over the past few weeks, I've picked it up again, and wanted to post my project to help anyone else, get input, and (mostly) to help as a form of motivation to see this through when I get frustrated.
What I've got:
Computer:
-I built the comp itself mostly out of old parts I already had. It's an ATX form factor. I have an Opus 150 to power it. We'll see if it draws too much power (one of my concerns...)
Screen: Xenarc 7" touchscreen.
GPS: Forget what receiver it was that I have, but it works great. I've got iguidance, and have used it with my laptop to test, and like it a lot.
XM: I have an XMD1000 that I had for my old radio. I just got an XM PCR in the mail yesterday.
Frontend: Centrafuse
The overall plan:
I was trying to keep my radio, and use it's aux inputs, but I have no idea how to fadricate AT ALL, so changed gears. Now I'll be running everything through the comp, then an amp to the speakers for the sound. I'll have a sub box in the back with my electonics bracketed to the top of the box, then a cover, so from the outside, it'll just look like a sub box.
I'm planning on running a single power line 1/0 to the rear of the car to a distribution block. From there, it'll split off and run 2 amps (1 for speakers, 1 for subs), the computer, and I picked up a thing to power usb hubs. It'll all go back to a single ground.
Long Term goodies: I've got my mp3s on the comp already. I'm planning XM and HD radio. I want bluetooth for the phone, eventually OBD II, and the GPS. (and any other goodies that catch my eye).
Where I'm at:
nothing is in the car except for the screen. That powers on, so that's a win

It's currently plugged into a cig lighter that is only powered when the car's on. I'm fine with that for now.
I got the XM PCR thing yesterday, and installed it onto my laptop just to check it out. I couldn't get a signal from inside the house. Tonight, hopefully can take it out back on the porch, and I'm really hoping, can pick up a signal. I also have the old antenna from my XMD1000 that's meant for cars. I'm going to try and plug that into it and see if that works too. If I can get XM going, I can at least have some music, even if it isn't through the car speakers yet.
This weekend I'm hoping to start some wiring and/or work on the sub box.
Well, that's where I'm at. I'm very out of my comfort zone here, so be gentle.
Cheers,
--Fish