I will upload photos of the 'secret entrance' to the Mission this evening, check below later...
Entrance: as Rancho Mission Road curves right, just south of Friars Road...
[NOTE: use the single center turning lane on the curve if you are unfamilar with the area]
Left side: Don't worry about the red "Fire Department Access" sign...it doesn't bite...
Right side: "Private Property, No Trespassing" does NOT apply to 5th Gen Camaros...