The first three digits make up the World Make Identifier (WMI). This tells you where the automobile was constructed. If the first digit is a 1, 4 or 5, it was inbuilt America. A "2" is used on this position for Canadian-constructed autos, and a "3" for Mexican autos. European-constructed automobiles use characters S by way of Z for this position. The second digit is the producer. That is "B" or "D" for Fiat Chrysler, and "C" or "D" for Daimler Chrysler. "C" can also be used for Steyr, a supplier to Fiat Chrysler. The last digit is the manufacturing plant.

When Ford finally cracked the muscle-automotive code, it made up for misplaced time. In 1968, Ford fitted a couple of Mustangs with a 390-horse 427, then changed that engine at midyear with the 428 Cobra Jet V-8. Rated at a conservative 335 bhp, the Cobra Jet was a aggressive powerplant with good street manners and an inexpensive price. In a Mustang or midsize Torino, it made for some of the best-driving muscle automobiles of the 1960s.