Update
Update for those that haven't seen this part of the film-----
I was taking another glance at the Hughes film video....note the Old Lady in Brown and the Texan. Those that aren't familiar with Dealey Plaza wouldn't know where these two could be walking from. I grew up in Dallas and I couldn't say. There is nothing behind them at all but the underpass. They are walking east on Main St where the parade took the turn on Houston. I cannot figure at all where they would have come from. Perhaps the train station but that is really long walk and best way from there is not through Dealey Plaza and Commerce St is on the far south side [closest to Union Sta] so these people just mysteriously appeared out of nowhere. It is noted that they seem oblivious to the pandemonium and like pissing into the wind they bulled ahead through the onrushing crowd. The old lady ....maybe she will make it to the next bus stop and the Texan striding ahead neither one even slightly turning their heads. The station wagon that first passes by is definitely a '59 Chevy. The video pauses a few times and replays the scene.