Which Fire Extinguisher?

[Blues]

Prompted by the thread running on where to place an extinguisher, which one is best for the car?
I would be looking to fix it in front of the driver's seat, on it's side.

[GreenV8S]

AFFF (water / foam) is the best sort. Alternatively you can use dry powder, but if you ever let it off inside the car (even for a trivially small fire) you will have the powder coming out of nooks and crevices for the rest of the life of the vehicle.

If you use AFFF you should know that there are two grades of extinguisher. The ordinary domestic ones are designed to be stored and used upright and only have a 3/4 liner. If you store or use them on their side it's possible for water to get behind the liner and pull it off, which will stop it working. Ones designed to be stored and used on their side cost quite a bit more and are the ones you'll see sold by the motorsport suppliers.