The third and fourth novels in the #1 New York Times bestselling Kinsey Millhone series by Sue Grafton: C Is for Corpse & D Is for Deadbeat.
In "C" is for Corpse, Bobby Callahan approaches PI Kinsey Millhone with a far-fetched story: a murderous assault by a tailgating car on a lonely rural road, a roadside smash into a canyon four hundred feet below, his Porsche a bare ruin, his best friend dead. Bobby, having suffered memory loss in the crash, claims someone had tried to kill him, but doesn’t know who or why. And he’s convinced Kinsey is the only one who can find out. In "D" is for Deadbeat, a man calling himself Alvin Limardo approaches Kinsey with a job that seems cut-and-dried: locate a kid who’d done him a favor and pass on a check for $25,000. It’s only later, after he stiffs her for her retainer, that Kinsey finds out his name is actually John Dagget, and his an ex-con, inveterate liar, and now dead. Kinsey soon realizes that Daggett had an awful lot of enemies--but would any of them go as far as murder?