The Camaro/Mustang rivalry had begun in 1967 with the introduction of the Chevrolet Camaro by General Motors. The Camaro was the largest threat to the lead Ford had in the "pony car" field, a market segment largely created by Ford with the introduction of the Mustang in mid-year 1964. The performance of the Mustang with 289 and 390 engines was not up to the Camaro, with its small block and big block V8. In an effort to improve the Mustang's image Ford made a 428 Cobra Jet V8 and a Ford Boss 302 engine optional for the 1968 mid-year and 1969 models, respectively. The Boss 302 C.I.D., engine was a created by combining a Ford Windsor, 302 cubic inch engine block with "large valve" Ford Cleveland, 351 cubic inch engine cylinder heads.
The Boss 302 Mustang was designed by Larry Shinoda, a former GM employee. The car featured a reflective "c-stripe". The fake air scoops in the rear quarter panel fenders of the regular production 1969 Mustangs were eliminated on the Boss 302, (only), models. A black horizontal rear window shade and a blackout hood were both options. It was one of the first production models with a front spoiler and rear deck wing. The name "Boss" came about when Shinoda was asked what project he was working on, he answered "the boss's car" because the project was a secret. Also Shinoda had called it the "Boss" as an homage to the new President of Ford Semon "Bunkie" Knudson who had brought Shinoda over from GM's Chevrolet Division after Knudson had left.
Source: Wikipedia (original)