when you have an alarm or remote start added you need to put diodes on the lock and unlock wires to allow the gem to "go to sleep" if you don't it will kill the battery very quickly.
I have factory keyless entry system. No aftermarket wiring additions as of yet...And (thanks ford) no under hood light was provided. Maybe they couldn't figure out a way to ground it to the plastic hood.
I have a metal hood on my 2006 XLT...