My guess is that we are now seeing the effects of deterioration in the starter cable/oil pressure sender/oil level sensor harness which includes the cable that connects the positive terminal of the battery to the starter solenoid. If this shorts to a pertinent grounding point it can carry full battery amperage and do some serious arc welding. In an earlier post I mentioned a torched 1994-95 wagon I saw in the middle of the road with the woman still in the driver's seat that I assume suffered that very fate. It is incredible that NHTSA has done nothing about this but got fully invested in the Prius unintended acceleration matter even though it was evident from the outset to any thinking person that it was driver error or, at least one well known instance, a hoax. So-called "junk science" at its finest. Mark