When I went, the Friday tour was also at 2PM, but the workers have Friday off, so it is quiet, and you get to go into some areas which are too dangerous during active assembly.
You stay with the group, but you can get up close, expecially on Fridays (I've done both Friday and another week day)
There are usually half a dozen or so finished and near finished units at the end of the line which you can go into. Could be any mix of sizes and lines.
"If the women don't find you handsome, they should at least find you handy." - Red Green