After watching the Glass house car chase with a xk8 and ferrari, i wondered what would be the best way to stop the vehicle if you suddenly had no brakes.
engine breaking perhaps, but can you downshift at high speed.
can't see the handbrake being much use.
my guess would be to quickly turn off the ignition and back to position 1.
thoughts please.

 

Turning off the ignition can lock the steering.
Modern brake systems have two separate hydraulic line systems, so you will usually have partial braking.
Emergency brake.
Rub the car on a curb (low speed) or along something like a wall (high speed).
Drive uphill.
Downshift (never tried this in an automatic)
Hit something that moves (easier on you)

I actually rehearse what to do in different failure situations in my race car.