[decryptthis_NSA]

IANAL, but it seems like there is so much precedent against vehicle searches that it's staggering that TSA thinks this is acceptable. Every case I've read related to vehicles indicates that probable cause is required for a car search

Maybe you have given up those rights by entering a special zone near the airport? Not justifying it, but maybe explaining it.

This is expected of the TSA, every bureaucracy will seek to justify and expand itself.

[swalkergibson]

Constitutional rights are never willingly given up. The "terrists" are winning.