At lunch while discussing the band, the amount of pastry that Daniel has eaten changes.
When Nick inserts the 8 track tape of the Rush album "Exit Stage Left" the tape player shows that it is playing program 2. The song playing is "Spirit of Radio" which would've been on program 1 of the 8 track tape of that album.
At the beginning, while trying to name the band, Linda Cardellini (Lindsay) looks right into the camera.
In the opening scene we see the 8 track tape for Rush's "Exit Stage Left" and in the closing scene we hear Nick listening to the live version of "The Spirit of Radio" from the same album. Although the episode takes place in late 1980, this album was not released until October 1981.
Daniel's guitar has a Misfits sticker on it, but it's of a logo they didn't use until 1981 (the show is supposed to take place in 1980).
While sitting on the sidewalk Sam starts saying that Cindy Sanders is a librarian type, but his lips don't move. It's clear that the sound track is originally from the next shot.