Wiring to the starter relay is as close as you want to go. Wiring to the battery cable gets you lots of very nice green terminals on your wiring as it ages.
As mentioned before, wiring to the battery makes for a very clean source as the battery acts like a gigundous electrolytic capacitor filtering noise on the electrical system. That is why if you start hearing alternator wine in your stereo, it is time to get a new battery or at least make sure the connections to the battery are good.


2014 Ram 1500 Laramie, 73 Cuda
Previous mopars: 62 Valiant, 65 Fury III, 68 Fury III, 72 Satellite, 74 Satellite, 89 Acclaim, 98 Caravan, 2003 Durango
Only previous Non-Mopar: Schwinn Tornado