when I clicked the link the picture was quite fuzzy at first, so I'm waiting for it to improve trying to work out what could be funny? rude words on the mileage? ridiculous mpg on the display? Even when the picture sharpened up it took me a while to notice the spider.
I guess it's a bit cold in the wing mirrors at the moment so he's moved to his winter residence.
I'm presuming you're not afraid of spiders, if that happened to some people I know they'd crash the car rather than take a picture.