Tail/marker light short circuit

My wife's car (06 HHR LS) is blowing fuse 69. I replaced it with an auto resetting circuit breaker, it would pop a few times, then be fine for a few minutes to a few days. Now it keeps tripping so when I find the short I'll know it. When it resets, the front marker lights and interior lights (radio and steering wheel buttons) light up for a second, but the tail and license plate lights don't, so I think the short is the power wire running to the back. I can see at the tail lights that the wires come in on the passenger side. Does it run above or below the door doors (or somewhere else)? I don't want to tear apart more than I have to too follow them.

Found it... A while ago, but I forgot to post an update. I had forgotten that my wife got bumped into at a stop light in October with no visible damage. It turns out the rear bumper support was nearly rusted into 3 pieces and it got pushed into the wiring for the passenger side marker light in the bumper. I thought those were just reflectors, I'm pretty sure they've been burnt out the whole 8 years we've owned the car.
I had the interior gutted and her car was out of commission for nearly 2 months trying to find the one stupid wire, but it's fixed now with a stronger rear bumper and I put all LEDs in it along with wiring resistors in so they don't hyper flash.