The easiest 12 volts to find in the 09 was the Aux connectors, can't remember which way around it was but one was 12v constant and the other was 12v with the ignition. It all depends what your powering and whether or not you have a second battery, I've got heaps of stuff inside the cab powered off the second battery but had I not put the battery in the tub and hooking the things up live was not an option I'd be like many others and use the aux.
As far as the ECU goes I've never upset one in any new car no matter what I've wired.
