And by "cheap," it may not only be the price that is cheap. :-)
I was in a store called "Five Below" (I'm in the Philadelphia, PA area, but they have locations in PA, NJ, DE, VA, and MD) and they have a number of Wii accessories, all for...yeah, you guessed it....$5 or below. They had Wiimote covers (the rubbery grippy kind), a steering wheel thing, a tennis racket thing...and some others. I didn't have a Wii at the time I saw them, so didn't pay a whole lot of attention to the specifics, but now that I have my Wii, I am going back.
If you load their webpage (http://www.fivebelow.com/) it actually shows a "Wii Racing Wheel" in the scrolling images on the homepage.