OAKLAND, Calif. -- Accused wife-slayer Hans Reiser verbally sparred with the prosecution for a second straight day Wednesday, claiming his cross-examination was requiring him to recall details "beyond my powers to remember."

In his sixth day on the witness stand in his trial on charges that he murdered his estranged wife Nina, a contentious Hans Reiser told jurors he tossed the a car seat into a Dumpster at Tim's Hardware in San Leandro, on Sept. 17, 2006.

The front passenger seat was missing when Oakland police found Reiser's car several weeks after Nina disappeared.

Prosecutor Paul Hora told jurors in his opening statement in Reiser's trial that Reiser may have removed the seat so it was easier to carry and dump Nina's body. But Reiser testified two weeks ago that the reason he removed the seat was that it was easier to sleep in his car.

He said he slept in his car because he didn't want to stay in the Oakland house where he had been living with his mother because that would hurt her chances of winning custody of the couple's children after Nina disappeared.

In a dramatic moment in court Wednesday, Hans Reiser inspected a replica of a Honda CRX passenger seat and demonstrated the motion he said he used to toss the seat into the Dumpster.

Nina Reiser, who was 31 at the time, was last seen alive on Sept. 3, 2006, when she dropped off the couple's two children at the house where Hans Reiser lived with his mother.

Nina, who was born in Russia and was trained as a physician there, and Hans married in 1999 but she filed for divorce in 2004 and was awarded legal custody of their children, although he had visitation rights.

Nina's body has never been found, despite extensive searches in the Oakland hills and elsewhere. But in October of 2006 Hans Reiser was charged with murdering her because prosecutors believe that DNA and blood evidence proves that he killed her.

He has pleaded not guilty to the charges against him.

Reiser's attorney, William DuBois has said that Nina may still be alive and be in hiding somewhere, possibly in Russia.