Step 10In closing
iImage Information

I hope you enjoyed this Instructable. If you do try this, bearing in mind the warnings from the front page, let me know/see your cups journey by tweeting about it and including "#RoofCoffeeCup" in your tweet so I and others can search for it. I usually tweet what reactions I have gotten, and sometimes where the cup is. If anyone asks, tell them what it's all about. I had some cheap business cards made up that I hand to people who get out of their cars/come up to my window to explain what it is. I've had more than one person laugh like crazy when I explain it.
The hurdle is trying to get it as light as possible, although getting the magnets to stay stuck on was a problem. Due to their powerful pull, as soon as you tried to pick it up off metal, the magnets would stay, and the battery cover would pull away. JB-Weld DOES NOT work well on magnets because it actually has steel in it, and is attracted to the magnets. I had to settle for epoxy so I can paint the outside of the phone b/c hot glue doesn't like paint.
it would work realy well with a sun-roof or what ever you call it!
you could even add felt pads on the bottom so the phone moves around on top of your car.
one last thought you could even have it beep every 15 minutes or so.
all realistic?
I saw one once that insisted it was a patented invention.