Speedtrap (1977)

After a wave of unsolved car thefts, an insurance company calls in private investigator Pete Novick to solve the case. While the chief of police isn't thrilled about having an outsider come and show up his men, one of the officers is a former girlfriend of Novick's who's more than willing to help him out in any way she can. After a long and convoluted investigation with false leads, psychics and the mafia, Novick at last unravels the identity of the thief.