Radfringe had a thread earlier (referenced below) about using your own store bought magnetic sheets to glue your bumperstickers to. When I saw it, I decided to finally reveal an invention of mine I created almost 2 years ago. I think many here would find it extremely valuable and it is quite easy to make. I'll copy the instructions that I already posted in Radfringe's thread. This is an awesome way to swap out bumperstickers on the fly or even every single day if you want. You can easily print your own as each day's event changes. For example, Helderheid posted a pair of bumpersticker slogans earlier that I combined a little and printed out in two minutes. And voila! On my truck it was. Here's the details:
http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=389x1116708#1116880"Ya take the same magnetic sheets, but cut it about a centimeter larger on all sides. Then, cut out the middle square which should be the size of the bumper sticker you want to use. Now you have two pieces; a solid center piece and an outer frame. Now take a piece of laminating paper (which is what I used, but any durable and thin plastic sheeting would suffice) and cut it to the exact dimensions of the outer frame, but leaving the center solid. Glue it to the edges and voila! You're done. Now just make a template in MSWord the same dimensions (use the ruler) as the inside square, and design ANYTHING you want in color. Print it out, cut it out of the paper, slap it right on the backing square WITHOUT glue, and just put the frame around it. The magnetic frame part will fit perfectly around the inner piece and all of the sides of it, including the backing square, will lay flat against the vehicle. This means the whole thing is sealed from rain. When you are tired of whatever sticker you printed, just take off the frame piece and put a fresh design right in! Switch it up in 10 seconds flat!
I've always wanted to share that here because it works great and you can literally print out a new message every single day if you wanted to and switch it up in seconds. The only reason I haven't shared it is because I still didn't know if it was something I could patent and market. But fuck it, it's been so long I might as well share it with my DU'ers. I hope you all like it! Maybe later I'll post a picture of it if anyone wants."
Here are some pictures (I gotta make a new one, as mine's getting old now. But you'll get the idea):