In 2007, Ford changed the design of the A/C knobs. This change required modifying the billet pieces. SilverHorse Racing is one of the few companies which was able to modify its pieces for use on '07-'09 Mustangs. To install the knobs (PN S197-525-07, $59) you have two methods available. One involves removing the lower console, the radio, and A/C control surround and removing the entire AC control unit before pulling off the knobs and breaking them as shown. The other method, which we employed, is to use a pair of pliers and pull them out breaking the same piece. In either case the factory knobs are not reusable. SilverHorse provides details for both methods in its instructions.