I have a 2kg extinguisher that I had to fit for the Caramulo hill climb. It mounts to two Rivnuts in the floorpan just ahead of the passenger seat cushion. Nuisance of a thing as it tends to rattle and I'm always a bit nervous of catching the safety pin then setting it off by accident. From the fire fighting courses I've had to do I'm with Britmog, any real fire needs running away from.