Wow, quite a bit of debate over my results. I chose to run Auto-Rx since I read somewhere on this forum that it was good to use on newer vehicles to help with break-in particles. I did not have enough knowledge of chemistry to know that it wasn't a good mix with Mobil 1.
As far as the extended interval, I didn't see it that way. I followed the manual's recommended mileage interval. Plus, it allowed me to rotate the tires at the same time. I thought the Mobil 1 would be plenty strong enough to run the 7,500 miles. Due to a lack of attention, I did run about 500 miles over that planned interval.
This run will be for 5,000 miles to see how metals look at that point. I have Mobil 1 AFE in there now without any extra additives. Her commute is 25 miles each way with mostly highway with some stop and go. The stop and go occurs a good 15 miles into the drive, so the engine would be warmed up by that point.