Character mistake: Janet is waiting for Larry to deliver her new car and states to Jack that this is her very first car. But 5 episodes earlier in S8-E13 "Itching for Trouble" when Moose asks if they had a football that needed air, Janet says no, but one of the tires on her car are low.

Three's Company (1977)
1 character mistake in Forget Me Not - chronological order
Starring: John Ritter, Don Knotts, Suzanne Somers, Joyce DeWitt, Richard Kline
Genres: Comedy

She Loves Me, She Loves Me Not - S8-E2
Visible crew/equipment: After Jack talks to Larry about the magazine quiz Jack asks Janet if anything's been bothering her, and just as Terri walks out of the kitchen holding the two cans, a crew member's hand can be seen behind Terri placing a bag on the counter. (00:04:15)
Jack Tripper: And speaking of current events, did you read the big news in the paper this morning?
Chrissy: The May Company is having a huge sale on pantyhose.
Jack Tripper: Excuse me, Chrissy, that's not exactly a current event.
Chrissy: It is so, it's going on right now.
An Anniversary Surprise - S3-E20
Trivia: Many TV stations over the years left out the original ending scene (the small party held before the Ropers leave). This scene explains how The New Landlord Mr. Furley knew Jack was supposedly gay in the first episode without anyone mentioning it. This ending reveals Roper told the new owners Jack was gay. Without seeing this ending, the storyline is unclear.
Question: During the first three seasons, all the main cast appeared in every episode (except one without Joyce Dewitt by season 3), but it seems once Suzanne Somers left the show, episodes had some cast members absent on a regular basis (mainly Richard Kline and Don Knotts who both only appeared in selected episodes in the later seasons). Was it a sudden budget cut or another reason for this?
Answer: Richard Kline and Don Knotts were supporting cast members, who could be replaced at anytime. It was John Ritter, Joyce DeWitt and Suzanne Somers who were the star vehicles they relied on to carry the show.





Suggested correction: It could have been a quick comeback line as a joke. The way Janet was even saying it sounded that way. Also, technically speaking, she did have a car in the past. The trio had bought Roper's Car for a very short time (from an earlier episode) before Roper bought it back from them. Janet never physically drove it but at that time, she was ⅓ owner of it so technically she had a car before.
Yes, I always thought it was a quick comeback.