There is no substitute for the factory manuals for your car. I have complete Ford manuals for my 93, my wife's 96 and our 96 Bronco. They've been invaluable over the years. Make sure you get all of the volumes for your vehicle. At a minimum, you'll need the basic Service Manual and you really should get the Electrical Manual. It goes into much deeper detail that the electrical section of the Service Manual. The Cobra will be covered in the Mustang books. The only reason I don't have them for my 04 Crown Victoria is that it's still under warranty.