When i bought my cuda the guy i bought it from never actually registered the car in his name, no kidding, owned the car for like 10 years and never registered it. I was young and really didnt understand the whole "sign the back of the title" thing. So when i realized it was never signed by the guy that HE bought it from i had to track him down. Being the gumshoe that i am, i had some old inspection slips from years ago that were in the car with the previous owners name on it. I found his name in the local phone book. (Hawaii is a small place) turned out he worked at an ABC store in Waikiki. I called his house and his mom told me he was at work. (guy was like 45 and lived with his mom still) I went down to the store and explained to him what happened and he signed the title for me, and i got it registered.
what a nightmare that was.