What a funny movie! I remember reading somewhere, years ago, that a sequel had been considered with Ferris working in a corporation.
Remember, that picture was taken right after his cover was blown. The sketches are after months of re-islamizing himself. The Al Qaida manual actually tells these guys to shave their beards of during operations.
The comment I should have made here is that the sequall would probably have been hilarious, but I'm glad they didn't mess with greatness.
Apparently the idea of a sequel to 16 Candles called "32 Candles" was kicked around, with the cast coming back and playing themselves 16 years later, but it never went anywhere.