With many modern cars coming equipped with an array of ultrasonic sensors mounted in the bumpers, it stands to reason that many junk yards have them too. [jimk3038] points out that, unless they’re crushed, they’re probably good. The list of features on these is pretty long, including being short proof, water proof, EMF proof and fast. These tough little suckers can be used in a multitude of projects and can have a range of roughly 2 meters. [jimk3038] documents in great detail how to use these things as well as offering some sample code to get you started. Why didn’t we think of this?