preface: stop street racing before you kill yourself or someone else.

That said, this instance interests me from an analytical perspective - specifically, I've never seen an XF pushed like this on a downhill course. The car seems to be totally stock, brakes and tires, and it shows the limits of the car in stock form when driven too quickly on corner entry.

By the way, based on the behavior of the car (oversteer/tail-out on the left hander ) I think your issue was less brake failure and more entry speeds that were too high - the last turn before the crash seemed to cement it. It looked less like you were following the line and more like you were trying for a *****-to-the-wall pass against the car in front of you (a catch-up-as-fast-as-you-can mentality.)

Racing on a closed road course gives you valuable racing experience that you can't get on the street. The reason is that street racing is largely "follow the leader", while road racing is "drive the perfect line". The difference between the two is that "follow the leader" usually leads to hot entries/crashes/death, while "driving the perfect line" encourages form, because going too fast into a corner causes you to deviate from the perfect line.