It would have been more fitting to include this car on the last numerical round, as 1964 was not only the first year for the Mustang, but also for today's car:
1965 Plymouth Barracuda.
However, given that '65 saw the first year a special package (the "Formula S") offered for the 'Cuda (believe it or not, it was introduced with a 170 cubic inch (2.8L for our metric friends). Horsepower was increased from the anemic 180 in the 4.5L V8 to 235, a more respectable figure (although nowhere near the numbers achieved with the 383, 426, or 440 cubic inch plants put in the later 'Cudas).
Most folks think of the '69 and '70 Barracudas, although that style remained until 1974. Gas crises and the rise of the Asian import helped bring about the end of the muscle car, and with it the end of the Barracuda. As gas lines snaked around the block, even the staunchest of pro-American drivers started looking at cars that got better than single-digit gas mileage.
Such is life in Detroit...
That is all.