[Ernest_at_the_Beach]

This would be one cell of the four.

Hopefully it will lead somewhere!

[aristeides]

This cell could account for the hijacking of both planes out of Boston, in which case this would be one cell out of three, not four. But whether or not there was another cell in Boston -- and thus presumably another vehicle with more evidence there, there are no doubt such vehicles to be found at the parking lots of Newark and Washington Dulles Airports.