Leicester Crown Court was told Iain Lawrence 53, of Ratcliffe Road, Leicester, had not come to terms with the break-up of his marriage.
The accident happened a day after an argument about finances involved in their upcoming divorce proceedings.
Mr Lawrence, who was not seriously injured in the crash, denies murder.
The court was told that Sally Lawrence's death was "a planned killing born out of grief, anger and jealousy".
Mrs Lawrence, 47, died from head injuries in the crash at Oadby in Leicestershire last October.
The court was told Mrs Lawrence's seatbelt had been unclipped before the crash and an airbag had been disabled.
The prosecution said the car had been driven deliberately into the tree with the passenger side taking the brunt of the impact.
The court also heard that Mrs Lawrence had often told relatives and friends that she was scared of her estranged husband.
The jury was told that police later found her car unlocked on the drive of the house with her handbag and overnight bag inside.
The trial continues.
A man deliberately crashed his car into a tree to kill his estranged wife who was travelling with him, a court has heard.