Hey Brad, in November of 2012 I set out to find my dad's car (70 Challenger T/A). I tried a lot of different things (banks, insurance companies, ownership trail, DMV with a picture of car and license plate) but came up empty.... I finally found some loan documentation that had the VIN on it and was lucky enough that Barry Washington, with challengertaregistry.com, had it in his registry. Long story short, I purchased the car and shipped it back to the states from Japan. So it can be done. Talk to anyone that was friends with your dad or family (uncle) and see what they remember, write every detail down, the smallest things could come in handy later. Search high and low for more pictures, documentation (can be DMV inspection, registration, insurance paperwork, loan paperwork etc). I know it is frustrating , I did a lot of work for about a month and came up empty until I found the VIN. It seemed like everyone I talked to said "find the VIN and I might be able to help". You can read my search thread on this site in the classics section. I actually came here to try to put out feelers and get some help, just like you are doing. There are a lot of great guys/gals on here that helped coach me and encourage me during my search. Good luck and let me know if there is anything I can do to help.
Koby
