Queasy Rider - S2-E1
Visible crew/equipment: When Doug is looking at the bike for the first time, all the stage lights are reflected in the helmets on the table. (00:06:00)
Queasy Rider - S2-E1
Visible crew/equipment: When Carrie gives Arthur the iron, six stage lights are reflected in the iron itself. (00:06:25)
Queasy Rider - S2-E1
Visible crew/equipment: When Doug comes into the garage and falls over for the first time, a tape marker is visible on the floor. (00:07:05)
Queasy Rider - S2-E1
Visible crew/equipment: When Doug and Carrie are arguing over the bike a white tape marker can be seen on the floor. (00:09:20)
Queasy Rider - S2-E1
Visible crew/equipment: When Doug is telling Carrie that he hates the bike, a crew member in blue jeans can be seen in the back of the mirror on the bike. (00:18:55)
Queasy Rider - S2-E1
Visible crew/equipment: During this entire episode, you can see lots of stage lights reflected in the motorcycles chrome parts.
Answer: Sara hasn't been mentioned in later episodes, and it suggested in later episodes that she never existed, and that Carrie is an only child. Kevin James stated that the producers couldn't think of an good plots to use with Sara, so they left her out.