The Shelby GT500 production numbers is an expected 8,000 units per year.
That is not at all limited. Don't expect values to increase significantly if at ll over the next 30yrs.
Cars as investments are really bad ideas. I would expect my cash to increase anywhere from 5.5-8% per year. Gonna be hard pressed to find a 2007 MY car that will incease by 5-8% per year.