Revealing mistake: When Cliff Booth is driving Rick's Cadillac, in some angles the speedometer is showing 0 (zero) as the car is driven down the boulevard.
Revealing mistake: At one point when Cliff is driving the Coupe the ignition key which is located on the upper dashboard is in the off position.
Revealing mistake: As Cliff walks his dog down the street, and out of camera view, the hippies' car headlights can already be seen reflected in the back end panel of the parked car along the street (waiting for their cue). The car headlights are fixed, as the car stands still "parked" for several moments before pulling into frame when Cliff exits stage right.
Answer: Yes, though the intention was not Tarantino's. What is onscreen is the trailer of the (real) 1970 film "C.C. and Company", which starred (as you might have guessed) Joe Namath and Ann-Margret. Said trailer showed their names twice, a stylistic choice that emphasized the film's stars, and Tarantino used the unaltered trailer in the film.