Paul's friend Jim Torp said: "Roger backed it in to the garage and Paul jumped in and said, 'Hey, let's go for a drive'.
"So they went for a little drive and this is what happened."
The Porsche was a mangled wreck following the fatal accident, but Torp said Walker - who is survived by his 15-year-old daughter, Meadow - "had to die this way" as he was such a huge fan of fast cars and spent a lot of his movie career acting in them on the Fast and the Furious franchise.
He added to the New York Daily News newspaper: "It's strange. [Walker] made his movies. He lived his life and he died fast and furious today. He loved speed, he loved cars, and he had to die this way.
"He died in a very fast car with his friend."
- Bang! Showbiz