Now forgive me for possbily missing something here..how could a passport survive a direct fireball impact?
Combined with the flight manual in the back of the car..this is getting a bit obvious isn't it?

This from BBC
Passport discovery

Rescue workers sifting through the tons of rubble earlier discovered a passport belonging to one of the suspected hijackers a few blocks from where the World Trade Center's twin towers once stood.

New York City Police Commissioner Bernard Kerik said investigators would probably be unable to identify the hijackers, because there were unlikely to be enough of their remains left to test.