The Car MD Vehicle Diagnostic Unit has been a Godsend to our family. The package consists of software to be downloaded to your computer (it is now compatible with Windows Vista), the actual unit which can hook up to the computer and in turn will be hooked to your car, a cable, and a carrying case. This nifty unit works when your check engine light comes on and is sensitive enough to detect if your gas cap is opened! Why I titled this peace of mind is that you are able to diagnose what is wrong with your car before you even take your car to the dealership or auto shop and they hook up your car to their computer system.. You are also not blindsided with what the cost of a part will be because the diagnosis also lets you know that. The bottom line is that you are now empowered and armed with knowledge so that nobody will take advantage of you-especially if you are a woman.