If you're in a bind to find an inexpensive Microphone Windscreen a.k.a. DeadCat, here's a quick tip shared by YouTube member krotoflik. Try grabbing yourself a padded furry (or wooly) seatbelt cover. There's a short sample with and without the Seatbelt cover on the microphone, and it does a decent job of eliminating that dreaded wind rumbling noise.
Available for about $6 dollars on Amazon is a sheepskin padded seatbelt cover, so does this technically make it a DeadSheep instead of a DeadCat? [Thanks Chad]