I need to find it again, once upon a time I got some apparently rare footage of the '89 Japanese Grand Prix from an old Japanese DVD that showed Prost turning into the chicane in last two laps he completed. His line was exactly the same both times.
Everyone thinks he turned in early. If you see that lap in isolation it 100% looks like he turned in early. I swear to you, he did not turn in early. He was taking those curbs every lap.