Spontaneous fire that began under the hood while sitting in the drive-thru line at a fast food restaurant. vehicle was running, but was stopped at the "pay" window. began smelling burning odor and then noticed light smoke coming from gap between hood and front quarter panels. while awaiting fire department arrival, flames became visible from the engine area and reached a height approximately 3 feet above the hood. vehicle had been driven several times that day and showed no signs of malfunction. in addition, there had been no recent work done on the vehicle. last repair to the vehicle was 6 months prior that consisted of body repair done on the opposite side of the vehicle.