Nice write-up on how to measure and build a copy of some odd car keys. Considering dealers now charge 80 and up for some of these keys, this is worth keeping in mind. Note, if you have an old or cheap car, you don’t have to worry about the duplicating the key, you can have Home Depot do it for $5 or less. Its only these new odd shaped keys that pose a problem.
http://www.instructables.com/id/Copy-a-Car-Key-with-a-3D-Printer/?ALLSTEPS