A bike bra will do the job best, and waaayyy better than electrical tape!

Here's a link to a good one, Scicon, at REI: http://www.rei.com/product/723020/sci-con-bike-defender



As noted upthread, the idea is not to keep the bike dry, per se, as they can take the water, but rather to prevent caked on bugs and grime, and to ameliorate the driven rain at high road speeds.