Walker, who leaves behind a 15-year-old daughter, was an investor in the Always Evolving car shop in Valencia, California.
While at the event, Walker and Rodas decided to take the Porsche GT out for a spin.
One witness, Jim Tort, who was at the event told the NY Daily News, Rodas' eight-year-old son tried to save his dad.
'I ran over afterwards, I was trying to find Roger's son.
'I found out his son had jumped the fence and gone over. He was trying to get his dad out.
Coroner Ed Winters said the bodies were so badly burned they would take days for them to be positively identified.
Witnesses at the crash scene posted a video of the scene on YouTube showing debris from the wreckage while emergency workers cordoned off the area. Photographs also show a burnt out shell of a car.
Friends of the star told a local newspaper they 'went through fire extinguishers' in a futile bid to fight the blaze that engulfed the car after the crash.
Antonio Holmes told the
Santa Clarita Signal: 'We all ran around and jumped in cars and grabbed fire extinguishers and immediately went to the vehicle. It was engulfed in flames. There was nothing.
'They were trapped. Employees, friends of the shop. We tried. We tried.'