While testing whether our October 2018 Model 3 was indeed now using Vision-only for Autopark (it does, and is apparently no longer restricted to Autoparking between adjacent vehicles using ultrasonic sensors), it was discovered that by creeping rearward with throttle after engaging Autopark (by pressing the blue "Start" button when presented), the system will (sometimes) sequentially re-target the next empty marked parking space. Experimentation suggests that this will occur a maximum of twice, for a total of three spaces consecutively selected. This was tested on both right and left sides of the vehicle (depending upon which side of the vehicle was positioned closest to passing available spaces).
Attempting to acquire beyond a 3rd targeted space resulted in cancellation of Autopark sequence in several attempts. Applying brakes at any point after engaging Autopark cancels the sequence (as always). This is likely not a feature, but an unintended behavior. Despite the slightly manual "override" nature of this behavior, the selection of a particular parking space is still determined by the vehicle system, and while the selection of a given empty space is possible, it is not certain - especially in circumstances where expediency matters.
