The first of two appearances of Speedy's cousin, Slowpoke Rodriguez; the other is in Mexican Boarders (1962).
Although it was probably for the comic effect, the Spanish song Jose sings in the beginning makes no sense.
The title "Mexicali Shmoes" is a pun on "Mexicali Rose", the title of a 1923 popular song and of two movies, of 1929 and 1939.
Part of the scene where Manuel is looking at Speedy's mousehole where he and José planted a large firecracker was reused in the 1966 short [Muchos Locos].
Although "To Itch His Own" is the last cartoon to credit Carl Stalling as composer for the Looney Tunes series, this short was partially scored by Carl Stalling as well, though he was not credited. The info comes from the Belgian Society of Authors, Composers, and Publishers.