All very interesting "intersections." Nice critical thinking! In the end I look at a few things that do not parse with conspiracies, and pre-meditation. #1) if what you want is for your wife to go away; and you live together; opportunities abound - privately. #2) it is unlikely a 2nd person was involved, because 1st Rachel would comply with a simple command to get in the car, add to that the life-long fear that your co-conspirator would talk. So, that guy would have disappeared that same day. TT did not need a 2nd person, there was no premeditation. #3) Finally, I cannot imagine a worse plan if it were pre-meditated. All evidence leads to a spontaneous act of domestic violence. Crime scene #1 is not the locked car in the parking lot. It is the car the girls got into with "someone they trusted."