Another new local here. All crime is horrible but when its both physically close to home and unexplained, it can really be unnerving.
A couple things that I'll add. I buy the McDonald theory the most as the reason for the longer gap in time from leaving work to the crime scene. One thing that has me bothered here is that I did the exact same thing at nearly the exact same time, traveling through the exact same intersection of the crime (but opposite direction) about a week and a half earlier. If anyone has a propensity for fast food, that seems like a high likelihood.
Additionally, I don't think she was exactly followed all the way from the bar. There is nobody out and about almost the whole path, so she would have been tipped off to a car tailing her fairly quickly. If she was creeped out at all she probably wouldn't have made a stop.
Here is a theory: This was a pre-planned hit job. Somebody might have watched for her departure from the bar at a distance. One suspicion I have is they then quickly got themselves where they wanted to be. I think this could be the 20-car "park" parking lot between the crime scene and the intersection a mile south with all these stores (walmart, mcdonalds, taco bell, gas station). You can see it on google maps - I wonder about what is going on there often. No lights, extra small amount of traffic along this segment of road past Dodge and Maple, etc. It would even be easy to get their out of the path of surveillance video if they were to have come from the North (opposite the direction Andrea went that night). They could have just waited to pull out when a/the vehicle came. From there I think the pulled around her and stopped or something like that.
That twitter picture is interesting. It makes me think the crime scene is larger than right beside her car. Look at all the (non-road?) cones to the west/right in the picture, and the second photographer and LE facing away from the apparent scene.
May justice be served.