... right before Bev shows the other kids her bathroom. Looked metallic (not common in the 80s) and round-ish (cars were usually squared). Also the couple in the same scene that somehow looked out of place (maybe their car).
Any possibility the crew could not block off the bridge but needed the shot?
Just saved a snapshot of that scene using VLC. Zoomed in... can't make out exactly what they are... two appear to be facing to the right of the shot; a third car is behind on of those two cars and it is facing to the left. The first two are squared off body styles. The third, more hidden one, is too hard to tell.
I don't know why you said a "2010's car" when none of them can be made out clearly even when going frame-by-frame.
Channelling Peter Griffin: "WHO THE HELL CARES?"