A Whittier man, arrested on suspicion of murdering a woman found dead in his car, was cleared after an autopsy indicated that she had died of natural causes, Brea police said. But Ted Lavack Jr., 51, remained in Orange County Jail on suspicion of felony drunk driving and felony hit-and-run driving. Bail was sat at $10,000 for the two counts, plus an additional $10,000 added for previous driving infractions, a jail spokesman said. Lavack's passenger was identified as Hope Ridgeway, 35, a jobless transient who had been living with him out of a 1975 station wagon. Lavack was stopped in a Brea industrial complex after he was seen driving erratically, and police then discovered Ridgeway's body. Two witnesses told police they had seen a station wagon matching the description of Lavack's car cause a traffic accident at the corner of Kraemer Boulevard and Birch Street. A coroner's spokesman said the exact cause of Ridgeway's death could not be determined until results of toxicological tests were received in six to eight weeks.