In the past there were various wires run down the sides of the drivers side door hinge that were hot 12V, could use a t-clip to fasten onto. That's what I did on my last car. The new one doesn't have the 12V in the arm rest anymore, it's in the middle storage area under the phone chargers. It's a good spot for daily access, not sure how easy to access the wires behind it, nor whether there's a better spot to find access. That's really my question, on the previous model many were finding alternative access.