We coordinated a group of Teslas at this location several times over the years, starting in 2013. I think the most we ever had was 7 or 8 cars....but remember, this was in the "early days." I live fairly close by. As an earlier poster said, you must be there EARLY if you want to line up together. And yes, some arrive at 5 am in order to grab the spots immediately in front of Katie's Coffee. We used to park around the bend in the other side of the same parking lot.
By 6:30 am, there will be lots of other cars arriving and since it is first come, first served, you likely won't be able to all park adjacent to one another. My recommendation is to be there by 6 am for the best chance to get adjacent spots.
Oh....and I just looked at the first photo in this thread. That is my blue X !