To appreciate how rare Shelby Mustangs are you need to see the total production numbers of all Mustangs by year. Take a look at these numbers. The Mustang was a very popular car even in the early years. The Shelby Mustangs are a small fraction of these numbers.
These numbers come from CJ Pony, a great place to find parts for your classic and newer Mustangs. I’ve spent a lot with CJ Pony over the years myself.
| Model Year | Mustang Production numbers |
| 1964 1/2 Mustangs | 126,500 |
| -Shelby Mustangs | 0 |
| 1965 Mustangs | 559,500 |
| -Shelby Mustangs | 562 or .01% |
| 1966 Mustangs | 607,500 |
| -Shelby Mustangs | 2,380 or .03% |
| 1967 Mustangs | 472,000 |
| -Shelby Mustangs | 3,225 or .06% |
| 1968 Mustangs | 317,500 |
| -Shelby Mustangs | 4,451 or 1.4% |
| 1969 Mustangs | 300,000 |
| -Boss 302 Production | 1,628 |
| -Boss 429 Production | 859 |
| -Mach 1 | 72,458 |
| -Shelby Mustangs 1969-70 | 3,294 or 1.1% of 1969 Mustang |
| 1970 Mustangs | 190,750 |
| -Boss 302 Production | 7,013 |
| -Boss 429 Production | 499 |
| -Mach 1 | 40,970 |
| 1971 Mustangs | 150,000 |
| -Boss 351 | 1,806 |
| -Mach 1 | 36,499 |
| 1972 Mustangs | 125,000 |
| -Mach 1 | 27,675 |
| 1973 Mustangs | 135,000 |
| -Mach 1 | 44,046 |
| Total Shelby American Cars built Cobras and Mustangs | 14,915 |