The opening credits answering machine message is referred to again in the episode itself, which is extremely rare.
Angel Martin only appears as the voice on the answering machine in the opening title sequence and briefly in a second message. In the first message Angel tells Jim about a tip on a horse race, which he purports to have received from "Eddie Tallafero," who was a character in the episode immediately preceding this, "The Battle-Ax and the Exploding Cigar," but not a character in this episode.
When Rockford's asking questions about the woman driving the Porsche, the "Porsche" lettering above the garage doors has been altered to "Rorschey" (so as to avoid trademark infringement) with the "Y" a different size and font from the other lettering.
In this Rockford Files episode from 1979 Valerie Pointer is a love interest of Jim Rockford's from 20 years ago. Patricia Crowley and James Garner were both in The Rivals, Maverick (#2.18) which aired in 1959, exactly 20 years prior.
The footage of Rockford's car making a right turn onto a highway to follow the Porsche was used in other episodes, such as Piece Work (1976).