During riding season, I keep one of those big Rubbermaid tubs (with lid) in my car. Inside is all my biking gear. After a ride when things are damp, I have to take it out to dry, but before rides it hides my gear when I park (I drive an Element so don't have a trunk) and looks non-descript when I leave it in the car during rides, not like it's full of pricy stuff like a fancy gym bag might. Works for me, and a lot less pricy than the bag at the Terry site.

Emily