In early season one episodes, Dennis was referred to as "Lt. Becker". His rank was later changed to Sgt. when they realized it would be better to have someone above him (Lts. Diehl, then Chapman) who would hate Rockford.
After opening the car trunk in the grocery store lot the scene shifts to the corner by the police station. They use a stock film clip that has been used half a dozen times before over several seasons which shows a red MG with a dented door making a left turn and a motorcycle cop coming the other way thru the intersection.
Byron Morrow, who portrays Deputy Chief Towne in this episode, was featured in 6 episodes, throughout the series' run, never playing the same character twice.
A real blue-boxer, John Draper, became famous as Captain Crunch because (according to Wikipedia) "a toy whistle that was, at the time, packaged in boxes of Cap'n Crunch cereal could emit a tone at precisely 2600 hertz - the same frequency that was used by AT&T long lines to indicate that a trunk line was ready and available to route a new call."
The last of four appearances in the series by Bucklind Beery, the son of Noah Beery, Jr.