Although it looked like a report from the Twilight Zone -- 52,000 U.S. Mazda6 sedans recalled because of spiders weaving webs in a vent line that could possibly cause a fuel tank fire -- arachnid incursions of that kind are actually fairly common.
"For those of us in the Southwest, the big problem inside our cars is a real desert denizen -- spiders," Mary Manning, a former senior reporter at the Las Vegas Sun, told me. Encountering a large, hairy spider in your car while on the road can be a real traffic hazard, to put it mildly. Manning found a huntsman (a spider the size of a half dollar) in her car on an afternoon drive around Las Vegas. It crawled on her husband's hand before she was able to knock it off with a pillow and usher it outside.
They like it dark
Spiders like to nest in dark, enclosed spaces, and that's what the yellow sac spiders in question were trying to do in those Mazdas. And it's not just the gas tank you have to worry about.
Messing with a nesting yellow sac spider is a bad idea because the female guards its nest zealously, and the little suckers bite. The venom won't kill you, but it hurts, causes redness and swelling, and lasts for 72 hours. Yellow sac encounters are a winter phenomenon -- they're the most likely spider to bite you at home, but they prefer the outdoors when it's warmer.
Mazda has no idea what it is about the vent line that attracts yellow sac spiders, but they've been found in 20 different Mazda6s (2.5L models built between April 2008 and February 2010). "Perhaps yellow sac spiders like to go zoom-zoom?" said Mazda spokesman Jeremy Barnes. You'd think they'd prefer the Ferrari Spyder.
All kinds of rodents will nest under car hoods, and European pine martens have been known to eat wiring and other rubber bits in BMWs. An American hazard is porcupines, which in Idaho often chew right through tires.