With all due respect to Steve McQueen’s Highland Green costar, Mustangs were actually getting creamed on the street by Chevys and Mopars, and it took a car dealer to fix the problem.
Tasca Ford in Providence, Rhode Island, was a hub of Blue Oval performance. Bob Tasca, Sr., sold a lot of Mustangs, but his customers weren’t satisfied. “We found the  so noncompetitive, we began to feel we were cheating the customer,” Tasca’s performance manager, Dean Gregson, told Hot Rod in 1967. “We had to do something.”
What they did was crank up a 428 Police Interceptor with 427 low-riser cylinder heads and a special cam, put it in a Lime Gold coupe, and gave it to Hot Rod to test. The response was so strong, Ford created the Cobra Jet Mustang the following year.
[Editor’s Note: This story originally appeared as part of the 25 Greatest Mustangs cover story in the July/August issue of Hagerty Drivers Club magazine. You can find the other entries here.]