Installed the remote starter kit (0000-8F-L82) in my '13 GT over the weekend. What a chore! It really wasn't all that difficult, but you have to basically take the entire front upper and lower dash apart. I mean nearly everything! Center console, glovebox, everything. The included instructions are great, and have every single detail you'll need to complete the job. If you've never done it, give yourself a good 5+ hours to slowly and carefully follow the directions. I could probably do another in 2 - 3 hours start to finish. FYI, I'm in the northern Virginia area if anyone needs help!
If you have any intention of replacing your stereo, now would be a good time to do that as well since everything you need to take apart is already done. I did the stereo first.....
The 0000-8F-L82 kit was indeed all that is needed for the GT, as it already has a hood latch sensor in place. Some dealers will require an installation kit (BHP1-V7-630). Looks to be the instructions, zip ties, foam pads, splices, and the cable that connects the immobilizer to the start controller. Best I can tell though is the remote start kit includes everything in that install kit. At least mine did.
Anyway, for $90, it was one hell of a steal!