The vehicle had been driven for about 35 minutes at approximately 70mph on the interstate. the vehicle unexpectedly began to produce a thick white smoke. the vehicle was immediately pulled over and placed into park; the vehicle was already on fire upon exiting. the grass beneath had caught on fire as well. the hood began to blacken indicating a fire in the engine compartment close to the firewall. the entire incident took place in about thirty seconds; from the time it began to smoke to the time it was on fire begin the entire incident. a truck driver with a dry chemical fire extinguisher put the engine fire out; after lifting the hood to a ball of fire. the only injury begin light burns from lifting the hood. essentially, my jeep wrangler, with no aftermarket parts installed, burst into flames for no apparent reason. *tr