The DEA agents, mostly Hank, are mulling over the word "culvert" during the stakeout. Hank suggests its etymology is Dutch, while Gomez guesses French. The origin of the word is unknown for sure but is most likely a combination of 'coule' (stream in French) and 'vaart' (Dutch for a small canal), so it is possible they're both right.
Hank says "don't miss your shot Ansel Adams, we need this guy." Ansel Adams of course is a famous photographer for capturing shots.
When Saul is talking to his two clients he says "You're golden, Ponyboy." This is a reference to S.E. Hinton's book "The Outsiders".
The episode title "Namaste" - from from Sanskrit "namas te" (obeisance to you) - is also the license plate of Howard's 1998 Jaguar XJ8 (NAMAST3).