Levandowski previously admitted to downloading thousands of files relating to Google's self-driving car project onto his personal laptop in 2016 as he was preparing to leave the company.
General Motors and Nikola have been in ongoing talks about a potential partnership deal worth $2 billion.
Residents of an Arizona city are slashing tires and even pointing guns at the vehicles.
In an unusual move, the Justice Department shared information with the judge just days before the case began.
The ride services company fired the leader of its self-driving unit, Anthony Levandowski, after he failed to comply with a court order.
Morgan Stanley analysts estimated Alphabet's self-driving car division to be worth at least $70bn, based on growth forecasts up to 2030.
Former Alphabet self-driving unit executive Anthony Levandowski allegedly downloaded confidential documents before leaving to join Uber.