Trabaja in the Baja

A job (trabaja) to be done down low, generally in the ass. Sometimes used to describe having had sexual relations in the ass with someone ugly.

John: look at that chick, I'm going to do a Trabaja in her Baja.

Joe: yo do you remember that ugly ass bitch from last night?
Dan: aw man don't tell me you did a Trabaja in the Baja?