While Lorelai and Rory are cleaning out their garage, Rory finds her old, almost completely faded, Hug a World pillow that she has not seen for a long time, in the season 2 episode "A Tisket, A Tasket" you can see a much less faded version of the pillow on the couch inside their home.
In this episode, Lorelai's garage appears out of nowhere to give Lane's band a rehearsal space. Prior to this, it is never seen, and is mentioned only once, that opens with Lorelai promising Lane use of the garage.
During the wedding at the Kim family home, a soloist performs the classical music piece Ave Maria, complete with lyrics. Mrs. Kim, the host, is a devout Seventh-day Adventist, and as such would be highly unlikely to have approved the singing of a song from the Catholic tradition, despite the fact that the lyrics are essentially a biblical quote.
You can see a reflection of what appears to be a camera man in the garage door window.
When Rory and Lorelai are about to open the garage doors, in the window behind Lorelai you can see an arm of crew member.
When Rory and Paris are seated in the headmaster's office, you can see the shadow from the boom mike and pole on the back wall.