I will give you 0.1%, given that there has been one fire so far due to an accident, even if it was some drunk moron running his S into a concrete barrier. But this is not about accidents, it is about common road hazards: receiver hitches, tire irons, rebar, pretty much any random piece of steel longer than a few inches. Fuel tank punctures from road hazards in a typical car are extremely rare due to being in the back of the vehicle and sitting higher off the ground as compared to the body pan and suspension. Tank punctures only happen in accidents, and I will gladly attest to how sphincter-loosening-scary that is. But, again, this is about road hazards. The worst case for an ICE from road hazard is generally getting a hole in the oil pan or transmission pan/case, but it doesn't happen very often due to the small target size and the fact that they sit a little higher than the suspension and frame. Regardless, if such does happen to an ICE, it does not result in a total loss fire, whereas at the moment, such is almost guaranteed with the Model S pack. The surest way for Tesla to kill their brand is to deny that there is a problem. But, on the other hand, when there are 1-2 road hazard fires a week a year from now, given the incident rate (~every 50 million miles) and production rate, these won't be newsworthy.