Kelso's (Ashton Kutcher) slip on the couch when he goes to talk to Laurie was accidental.
Last episode to be set in 1976.
When Ashton Kutcher (Kelso) trips on the table, you can see Lisa Robin Kelly (Laurie) break character. Her reaction was genuine.
Eric's car is confirmed by a State Trooper as a "1969 tan Oldsmobile station wagon".
Red & Kelso play a game of Pong at "Bargain Bob's". You can see that the paddles are normal sized. In a later episode, Kelso takes apart Red's Atari to make the Pong paddles smaller. Red agrees to help him because the old way was too boring.