I do not wish to offend. If you consider yourself sensitive, please, scroll and roll. TYIA
Whether the vehicle in SWFA's parking lot is related to our SP or not only matters if the vehicle can be placed at the CCoC. Here is a hypothesis to consider.
Let's say that the car can be placed at the CCoC. We do not know yet how the Altima was attained but it is not the SPs usual vehicle. It may have been secretly purchased in LA. Whether the Altima is involved or not, for all practical purposes, we know SP was lying in wait somewhere in the SW area of the Church.
MBs purse and personal items are left inside of her truck. Hence, I timed how long it would take to exit a truck, open the tailgate then, perhaps, remove something lightweight then, unlock and open the first outer locked door at the SW Corner of the Church. Remember that the inside glass door is propped open. We see that propped open door in the video when SP marches over to the Dutch Door.
SP was well aware of the very narrow timeframe required to make this work. The only way the timeframe works is if there is no struggle. At 4:23, MB enters the building, I believe, within moments, SP aimed a laser light and shot once, as an expert marksman. The weapon causes some of the gait issues. SP is able to puncture with the tools after removing the dart in a determined effort to make it appear there was no shot at all. In other words, only the SP should know there was a shot and that the ammo is missing. SP is out of the building by 4:30.
SP removes themselves from the CS by exiting without being seen on camera again. SPs vehicle is in the back parking lot. SP drives away a full 4 - 5 minutes before the first camper enters the parking lot at 4:35am.