Definition: Compose a new way to ask the same question. The new question must be asking the exact same thing as the original question does. Without any other information, you should be able to tell that the original question and the new question are the same. Preserve bracketed phrases in your new question. You can change the rest of the question provided the above requirements are satisfied. The new question must have a natural, fluent formulation, as if it were composed by a native English speaker. You will be given three pieces of information to help you create better questions. Those are: "Answer": the answer to the question, e.g., "Honolulu". "Answer Type": the type of the answer, e.g., "Location". "Auxiliary Information" is a detailed description of some concepts mentioned in the question, if any.
Input: original question: Which automobile generation is the successor of [Fifth Generation Ford Thunderbird]
answer: fourth generation ford thunderbird
answer type: Automobile generation.
auxiliary information: The fifth generation of the Ford Thunderbird is a large personal luxury car that was produced by Ford for the 1967 to 1971 model years. This fifth generation saw the second major change of direction for the Thunderbird. The Thunderbird had fundamentally remained the same in concept through 1966, even though the styling had been updated twice. The introduction of the Ford Mustang in early 1964 had, however, challenged the Thunderbird's market positioning. It, like the Thunderbird, was a small, two-door, four-seater with sporting pretensions, but it was substantially cheaper. The Thunderbird's sales suffered. Ford's response was to move the Thunderbird upmarket. For 1967 the Thunderbird would be a larger car, moving it closer to Lincoln as the company chose to emphasize the "luxury" part of the "personal luxury car" designation. Ford chose to abandon the Thunderbird's traditional unibody construction for this larger car, turning to a body-on-frame method with sophisticated rubber mountings between the two to reduce vibration and noise.

The successor of [Fifth Generation Ford Thunderbird] is what automobile generation?