I hear about car fires every now and then on traffic reports, for example. What are the typical causes of car fires? - Jinx
Electrical short due could be one way (which could be due to wire terminals coming loose, heat melting insulation, vibration wearing through insulation), once the wiring catches on fire, then there’s all sorts of belts and hoses to burn.
I had an old Ford Escort catch fire once. The top of the engine was dirty with old oil and other stuff. When the car backfired (which is fire backing up through the carbeurator), the oil caught fire. Which melted the wiring harnesses and caused other damage. There was a county sheriff in front of me at the traffic light, and he got out with a fire extinguisher and put out the fire. But since it was a junker it was pretty much a total loss because of the engine damage.
A lot of fires are caused by a fuel leak. If the hose after the fuel pump gets worn it can break, spraying fuel all over the hot enginer where, it being fuel and all, it burns. Cars go up quick when they have fuel fires.
Electrical fires can also cause fuel lines to break which then causes a fuel fire, also resulting in a very fast car-b-que.
Batteries can also leak hydrogen (not so much a problem these days, but much more common 20 or 30 years ago). Then all you need is a good spark and the battery goes FOOOOOM!
If you car catches fire get out of it QUICK. Cars can go from smoldering to a raging bonfire that roasts your nuggets from 50 feet away in a very short amount of time.
My 82 Ford Fairmont caught fire when the exhaust pipe burned through the bottom of the car and ignited the back seat. Was fixed by placing a metal plate between the burned seat and the floorboards. Doper NPavelka was sitting on said seat at the time…
A truck I borrowed from my in-laws 
caught fire when the throttle stuck wide open; I was in the middle of the freeway, and pulled over to the side with the engine revving like crazy, the brakes barely holding to rush-hour speed. I then shifted to neutral while trying to fix it (kick the pedal, turn engine off and on, etc.) The second time I turned the engine off, it wouldn’t stop running, it just kept revving – and then I saw the smoke.
Fortunately, it was a very old truck, replaced with another very old truck, and my in-laws weren’t too put out.
That year, I got a fire extinguisher for Christmas. Wiseguys!