I'm sorry your information is incorrect. Before retirement I was a Risk Analyst (Fire, Theft etc.) and if I recall correctly the flashpoint of petrol is -43 degrees C. whereas the flashpoint of brake fluid is typically greater than +135 degrees C. I recommended a dry powder extinguisher, as this is the most versatile coping with flammable liquid, electric fires etc. and therefore most suited to cars. A messy clean up is not an excuse for having the incorrect extinguisher.