It's interesting that you posted this, Brian. I recently looked out of curiosity, and was amazed at the numbers / increase on 66 Shelbys (again, non-Hertz, Carryovers, etc.).
It does seem that 66s have gone up quite a bit in value, and the same could be said for 65s and 67s - I haven't looked at 68s and beyond.
Incredible!