One might wonder why Eric would find Casey Kelso calling him "Foreplay" objectionable...that is, until one realizes Casey is implying that Eric merely warmed Donna up for him.
Invoked by Hyde upon learning that his real father is black. According to him, it explains "my fro, my inherent coolness, my constant suspicion of the man."
Maybe not brilliant, but a certain Fridge Logic about the dates as shown at the end of each episode: the plate stickers on a car don't denote what year it actually is, but what year the plate expires. This can be up to two years beyond the date of purchase.
Red was always on Eric for his Star Wars toys and making references to the movie. This is just Red being Red... Until you realize Kurtwood Smith played in a Star Trek movie before this show. He's a Trekkie picking on a Star Wars fan!