And let it be said that a lot of people would be happy with "SS"'s new car--which, even if it was dumb luck, was not that easy to win.
In "J!"'s case, I had the feeling that the staff knew that they were on borrowed time--they just saw "Concentration" go down and they knew that they were not Lin Bolen's kind of show. Bringing that bonus in was an attempt to keep the wolf from the door, but they knew that she was going to get rid of them sooner or later--especially anyone who knew that Merv had already proposed a show more compatible with her vision of NBC daytime game shows.
Perhaps they could've increased the values, but unless they changed the host, made the material more pop culture or wacky polls, glitzed up the set and ramped up the sweetening as well (and even then that's questionable), they were not long for Lin Bolen's world.