The Marin County panel on Wednesday found 19-year-old Max Wade guilty of commercial burglary and auto theft, after hearing evidence that Wade had rappelled into British Motors in 2011 to purloin the $200,000 convertible. The car was in the shop for repairs at the time.
He was also found guilty of attempted murder and firing a gun into an occupied vehicle in connection with an unrelated drive-by shooting of a man who was dating a girl Wade desired. The man was not injured in the shooting.
Marin County prosecutor Yvette Martinez said Wade had stolen the yellow Lamborghini to impress the girl, and was willing to kill to get her attention.
Wade pleaded not guilty to the charges, and faces a maximum of 30 years in prison. He is scheduled for sentencing on Dec. 16.
Detectives testified during the trial that they found the gun used in the shooting, two assault rifles and shotgun shells, as well as climbing gear.
Food Network star Fieri testified during the trial that he had never met Wade, and never gave him permission to drive his car.
The teen made news again last year after two people tried to break into juvenile hall with sledgehammers in an unsuccessful attempt to free Wade.
Authorities took extra measures to ensure security in the courtroom during the trial, keeping Wade tethered to a chair bolted to the floor.