The Pacific Grove PD desk sergeant mentions the "Pro-Am golf tourney in Monterey," a reference to the Bing Crosby National Pro-Am played at Pebble Beach every year. However, the tournament was (and still is) played on courses at Pebble Beach, which is not part of Monterey and a PG police officer would have said the "Pro-Am golf tourney in Pebble Beach."
Rockford confronts Ralph Correll on the "penthouse only" elevator. The elevator would only stop at the penthouse and ground floor, would make it impossible for Rockfiord to catch him on a different floor.
When Jim leaves Los Angeles for San Diego according to the sign he drives north on California Hwy 1.
When Rocky exits the trailer, we are shown a view of the surf through the door when we should be seeing a parking lot.
When Jim lands in Denver, the establishing shot - a low brown-stoned building on the left, with the tops of (4, in total) skyscrapers to the right,'is, in fact, NYC (the mid 50's and Park Avenue, to be exact). In fact, the first skyscraper to the immediate right of the brown-stoned building is known as Lever House (390 Park Ave.); an iconic building designed by Grdon Bushnell.