I think we've done this one before. Car fires can be very difficult to put out, sometimes the amount of water on the Fire Engine isn't enough. 1 small fire ext generally will not be enough. There are other concerns that the Fire/EMS people on the forum can address better than I. Explosion, toxic fumes, etc. I saw video of a car fire that the FD was having trouble with, a large construction water truck came by and that had enough water, but it had a 5 or 10, 000 gallon tank.

Dave