I got lucky in my 2013 when I activated my remote start, wiring was 100% there already.
I installed the ajar switched hood latch, ordered the correct fob, programmed it with alfaobd, changed the settings in the bcm for remote start with alfaobd, and had factory remote start.
Boosted Motorsports has some great videos on how to
program the keys and
activate remote start with alfaobd.
Check to see if there's a connector near the hood latch. If you do, there's a good chance the wiring is there already. And if you do have it, check the connector for corrosion. They just leave it dangling there with no cover or anything. Mine was so corroded I had to replace the entire connector/pigtail.