We need to isolate the problem. To do this you are going to need to have the autostart unhooked from the ignition and starting circuits in order to determine if the autostart is the problem . I am not suggesting removing a fuse i mean unplug the wires where they plug into the ignition on the steering column. It is also possible you have a fuse panel that has had water intrusion and shorting internally to power , water is known to enter the cabin on your model from poor windshield sealing. Either of these could be the fault so this is why isolating is neccessary.