First a tiny bit of history: Way back, in the Roaring 20's, UL had a falling out with Henry Ford. Since then, the auto industry hasn't had the slightest interest in what UL has to say; Henry was confident that his guys knew more about building cars than anyone else.
Looking back, I think Henry has been proven correct. The auto industry -naysayers like Ralph Nader notwithstanding- have done a monumental job in perfecting the automobile. It IS pretty arrogant for someone to assert that 'they' don't have any method behind their madness.
Without knowing the intimate details of the design, there are a few points to consider.
The first is an engineering call as to the classification of the location. Gasoline has a pretty narrow range where there's the right amount of fuel and air for an explosion to happen.
Second, there are very likely two approaches taken by the designers that further reduce any risk. The very 'weakness' of the components may result in the quenching of any explosion by venting the pressures, and the circuit itself just might qualify as intrinsically safe, lacking enough current to be able to ignite the fuel.
As if to illustrate this point, I remember some clever soul claiming that an effective 'car bomb' was to break a bulb and stick a tail light in the tank. Step on the brake, and BOOM! Yea. right. Without getting into the dirty details, I once saw this attempted under laboratory conditions, and the most that was ever accomplished was popping the gas cap off. This wasn't the first time I've seen Hollywood debunked.
