Covercraft Weathershield cover from Autoaccessory.com
I got mine from www.autoaccessory.com, fits fine, I believe it's made by Covercraft (see their site at www.covercraft.com for more info, but they don't sell direct). it's compact and lightweight, waterproof, but not cheap. if you're looking for protection against bumps, the Weathershield cover won't help, it's very thin, but otherwise seems to do a good job of keeping stuff off the car. I haven't used mine too much yet, but I like it. if you don't want to use the antenna pocket, you can just folt it inside out, and unscrew the antenna before putting it on, and either put the antenna in the trunk or stuff it into the folded-in pocket.
a couple pictures:
<img src="http://pictureposter.audiworld.com/15438/cover_side_with_antenna_pocket.jpg">
<img src="http://pictureposter.audiworld.com/15438/cover_back.jpg"><ul><li><a href="http://www.autoaccessory.com">http://www.autoaccessory.com</a</li></ul>