The vehicle's innocent conduct created sufficiently particularized and objective reasonable suspicion for the stop, given the experience of the officers.
Special Concur: True according to precedent, but problematic to use innocent conduct as basis for border stops.
http://cdn.ca9.uscourts.gov/datastore/opinions/2018/08/31/16-50490.pdf
Since 2011. An occasional commonplacing of the U.S. Circuit Courts of Appeal.
Neither an authoritative statement of the law nor legal advice. Quick work.