I'm just surprised that out of all of Germany, the FDP has no areas that they have a concentration enough that they win direct seats.
They almost certainly could if they tried. Seats where the CDU is in first and the FDP is in second would easily vote FDP if the FDP made an effort. But doing so would only hurt the CDU-FDP coalition as it would mean fewer CDU overhang seats with no increase in seats for the FDP. There's just no reason for smaller parties to seek local seats at all.
Of course, if the percentage change were to somehow be the same for 2013 as this time, the FDP would be the second largest party.
How did Vera Lengsfield do? Did the voters agree that she had more to offer?
How much would the results change if the 5% threshold were applied at the State level instead of the Federal level?