Roonan Senator Aang is based on Senator Edcel Bar Gane who was designed and filmed as a background alien for Star Wars: Episode I - The Phantom Menace (1999) but never appeared on screen.
The sign outside of the droid spa lists their various services written in Aurebesh. They include: oil baths, rust removal, memory flushing, polishing, motivator repair, de-fluttering, restraining bolt application and removal, general maintenance overhaul and junk removal.
The Hutts are intergalactic gangsters, therefore Arok the Hutt (with the cigar) is modeled after Edward G. Robinson and Marlo the Hutt is based on Marlon Brando as Vito Corleone.
50th episode of the show chronologically.