iding scale of intrusiveness, with more intrusive (Le., less "routine") searches requiring reasonable suspicion. See, e.g.. United States v. Molina—Tarazon. 279 F.3d 709. 711-13 (9th Cir.2002). Flares—Montana plainly repudiated that approach. Of course, Flores-Montano, Chaudhry, and Cortez-Rocha invo