"Playboys of the Southwestern World" is a song written by Neal Coty and Randy VanWarmer and recorded by American country music artist Blake Shelton.
[1] The song tells the story of Romeo and his wild-child neighbor and childhood friend, John Roy, two teens enroll in a small Texas college.
The two enter Mexico but are detained by a border guard, who suspects illegal activity due to their possession of cash in United States dollars, and threatens them with "ten years in a Mexican jail."
Since a "pocket full" of cash in a tourist's home currency is normally not reasonable grounds to suspect a crime, the song lyrics that compare the event to Paul McCartney's arrest in Japan for may be a hint that they had other items in their possession.
The chorus quotes a portion of Van Morrison's "Brown Eyed Girl", as well as interpolating the "sha-la-la-la" vocal.