Although there are already plenty of good bicycle fenders out there, some people don’t like the way they rattle around, while others think that they detract from the looks of the bike. One option is to use something like the QuickFix, which is a fold-flat rear mudguard that attaches to the frame in seconds. The Plume, however, takes a different approach – it’s a mudguard that recoils like a metal tape measure when not in use.
Invented by Dan McMahon and Patrick Laing, the Plume is made from a thin, flexible sheet of stainless steel, encased in a flexible polymer.
In order to first install it, the bicycle’s seat post is removed, squeezed through the rubberized mounting ring, then put back on the bike. This minimizes the chances of the Plume subsequently being stolen, and allows it to accommodate different seat post diameters – although fat mountain bike posts are still too big for it, so far.
To “deploy” it, the rider simply grasps the end of the mudguard between their fingers and pulls it out. When the roads dry up, grabbing its end and pulling up on it causes it to roll itself back into a tight little loop under the seat. According to McMahon and Laing, doing things like riding over bumps won't cause it to accidentally recoil.
They’re currently raising production funds for the device, on Kickstarter. A pledge of US$35 will get you one, when and if they’re ready to go.
The Plume can be seen in use in the video below.
Source: Kickstarter
Also i doubt you'd get slapped with this because its no where near your back, it would barely touch your back even if your stretched the tip of it up to your back. And you don't *need* a first one, it would be nice but one out of two is still better then none, alot of the under spray from the front tire gets blocked from the bike frame except when turning.