Starting in 1969, to aid sales and continue the winning formula of the Mustang, a variety of new performance and decorative options became available, including functional (and non-functional) air scoops, cable and pin hood tie downs, and both wing and chin spoilers. Additionally, a variety of performance packages were introduced that included the Mach 1, the Boss 302, and Boss 429. The two Boss models were to homologate the engines for racing. The 1969 Mustang was the last year for the GT option. A fourth model available only as a hardtop, the Grande, saw success starting in 1969 with its soft ride, "luxurious" trim, 55 pounds (24.9 kg) of extra sound deadening, and simulated wood trim.
Source: Wikipedia (original)