TB Rhine, let me take your second point first . . .
Way, way, way earlier in this thread, somebody also brought up the idea the manager and her husband might've randomly picked out a vehicle they saw on the street so as to cover up the actual vehicle involved in Jessica's disappearance. And as somebody else responded shortly after: Then where is the innocent driver of the Town and Country in those pictures? Wouldn't the person who owned the vehicle have come forward by now since the person has nothing to hide? Sure, maybe the person doesn't know anything about Jessica's case. But several people in Michigan do. And wouldn't one of them have pointed out to their friend--the owner of the gold Town & Country--that "Hey, that looks like your van!"? The lack of anyone coming forward to own up to owning the van in the picture is almost 100% proof that the van in the picture is in fact the one used in Jessica's disappearance.
As for your first point, the problem with the manager and her husband noticing that a family member's vehicle was at the store is that they would've been doing it from several hundred feet away at night. Either they would have only been able to see the tail lights as it drove in behind the store OR after it turned around and parked with its lights off. Frankly, I don't think I could identify my own car from that far away at night. Yes, they might have seen "a vehicle". But there would've been no one way to tell WHOSE vehicle it was or what kind or what make or what color, etc. until they turned around and came back, and got much closer.
I want everyone to think about one more point: The manager and her husband, if they are co-conspirators in Jessica's disappearance, would've been best off to say they saw nothing, i.e. they went by the store, saw nothing, and kept on cruising to wherever they were going that night. I mean, if you think about it, them saying they saw something that night has only made them MORE suspicious, not less. Even if they saw a van pull in there, turned around down at the next intersection, came back and discovered it was one of their own kidnapping Jessica, and if at that point the couple decided to cover up for their family member, why would the two of them say anything about seeing anything? The best choice is to say, "We didn't see anything when we cruised by the store that night." Then there would be no van. No timeline. No exact time of when Jessica disappeared. Etc., Etc., Etc. Her disappearance would even be a bigger mystery than it already is.
And there would surely be no heat coming down on the manager and her husband, if they kept their mouths shut . . . if in fact they are involved in Jessica's disappearance. Which I'm pretty sure they aren't.