If he returned to the Shell station to look for Danni after he left Ollies, it will be on CCTV footage. Either way, we know her car left the Shell station at 11:24PM.
Although I don't know how to confirm this, I have read here that the cars entered the Shell station from the right, and that Danni's car and Car 3 turned left at 11:24. That may mean something in terms of where they were headed - anyone local know whether this means anything?
I was very interested to learn that access to the Shell station is via a service road rather than the interstate, so anyone who was in the area at 11:08 would have been on the service road as well even though businesses were closed.
The long shot possibility is that two strangers in a random vehicle saw DW and Danni at the Shell station and decided to interact with them, but DW pulled out just as Car 3 pulled in and so Danni became a victim of random strangers who happened to be looking for a crime of opportunity that evening. The only unusual point is that they knew to disable the GPS (OnStar is what was first posted on Thread 1). Maybe this is something that all car thieves know?