Border checkpoints are administrative searches and require NO PC.
Many airport screeners are government employees now, and as such, these would also be administrative searches, as it is not practical nor constitutionally required to secure a warrant for every search, impossible.
Depending on what took place, any so called "furtive gesture/furtive movements" can give rise to permitted search in the area of such immediate control.From what I've read, Suspicious Behavior from the part of the driver can give the Officer reasonable suspicion, and therefore probable cause to do an inspection of his car.
Michigan v. Long, USSC, ruled an officer who has a reasonable belief a person may have a weapon at hand and can access it, the officer may search in that area. This ruling expanded Terry v. Ohio in which an officer could pat down or "Terry frisk" a person detained when they have a reasonable belief they may be armed.
I'm trying to figure out if attitudes such as constant refusal to show some basic documents (ID, drivers license..) is enough for the Officer to have grounds to perform a simple inspection in the vehicle. Keeping in mind that this is an area where drug smuggling is rampant, and undocumented immigrants exist in large number.
Cases that deal with this specific situation would also be helpful.
Thanks in advance
Firstly refusal to show a DL when drving can be an arrestable offense. Then the vehicle can be impounded.
IF other documents are asked for and not given the officer may be able to, in some jurisdictions, do what is called a "credentials search" and look through the glove compartment, visor, etc. Whether this doctrine is alive in NM, I don't know.

