Every car should carry a fire extinguisher of reasonable size and in a handy position. Anticipating the worst case scenario of being trapped behind the steering wheel in a crash I have fitted 2 extinguishers in the cockpit, both within reach of the driver. Each extinguisher is a 1Kg dry powder.
The following picture shows the two positions I have used: one on the sloping chassis member and the other in front of the passenger's seat. The one on the sloping chassis member is secured by self tapping screws into the frame. The one in front of the seat is secured by large cable ties.
I have been the driver in a car fire incident. It is a nasty experience. It is foolish not to have some means of protection on board while the occupants vacate the vehicle.