I think the Circle K and possible vehicle thing is a big deal. There are a lot of roads, a lot of gas stations on those roads, and a lot of cars driving by. For LE to go to a specific gas station and ask about a specific car (or even a specific make) suggests that they think they are onto something, IMHO. This is not like asking every gas station in the region about any car that might have passed by. It's asking one gas station about (presumably) one car.
Then again it's possible they did ask many other gas stations and it's just this Circle K that blabbed about it. But my gut tells me that this is an indicator of a development.