user: Question: Where the fastest lap is Mike Rockenfeller, who is the winning driver?
Columns: ['Round', 'Circuit', 'Date', 'Pole Position', 'Fastest Lap', 'Winning Driver', 'Winning Team']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['1', 'Hockenheimring', '1 May', 'Bruno Spengler', 'Bruno Spengler', 'Bruno Spengler', 'HWA Team']
SQL:

assistant: SELECT "Winning Driver" FROM "Table" WHERE "Fastest Lap" = 'Mike Rockenfeller';