How can I trace my '66 Barracuda's history?

Chrysler Historical came through for me on my 1966 IBM card and break down. This information provided at least that it was sold new in North Carolina. I did a DMV search on the car there and found the original owner based on TITLE search in the original dealer state. I bought the car out of California and they also, for a fee, did a title search, and gave me ownership information for the car while it was in california. As Mark states googling those owners and cold calling them can provide some details, getting old pictures, sometimes even a file that has old documentation.....

good luck....