That was a thought to me as well, kids have been in the car and JOK as well of course. KR took them around to anywhere they needed or wanted to be as well. It seems more likely that this is what transpired, it came from inside the car. Just that the two photos are different and that hair is super tiny. How was it found? Did someone there do a vacuum for hair? We know pretty much that those taillight pieces were not found at the scene that morning. Fits in with the scenario. IMOMy theory on the hair...
It was in the car and whoever was in the car, the tow truck driver, crime collection staff, LE, whoever was physically in the car could have inadvertently brought it out with them. It doesn't even need to be "planted".
JMO