I wonder how many gaping holes we can come up with for this one?
Let's try -
1. The valets are untrained so wouldn't know what to look for
2. The rationale for searching is because they're parked, but twerrists could still simply drive up and detonate a bomb. (Unless suicide bombers aren't willing to go to ROC, which is distinctly possible now that I think about it - I know I wouldn't go near the place)
3. IIRC, the law says that an administrative search has to be done in a manner consistent with a specific stated purpose: "car bombers" means that every vehicle entering or approaching the airport terminal must be searched.
4. No mention of searches of delivery vehicles which also park near the terminals for extended periods.
5. Is there an employee car park near the terminal, because that would need searching every day too.
6. What do they do if a vehicle is sealed or parts of it are sealed and they can't gain access? Do they break the locks on truck storage containers?
7. How does their search deal with all those bombs

hidden in the chassis or out of sight?
8. About that pesky Constitution and the search limits...
Next?