Vintage Cars: searching car with 11 digit VIN, washington state dol, insurance database

Question
HI, I know this is a strange question, but I'm kind of desperate. I was recently notified that I have credit collections against me for a car that I used to own that got ticketed/towed/impounded. I sold the car over 12 years ago, but the Washington state DOL has no record of the sale/release of interest, making me fully liable. The car is a 1979 Datsun and because the VIN is only 11 digits, I'm having a hell of a time tracing who has been driving it for the last 12 years.
I would greatly appreciate any help on the subject.
Thanks

Answer
I'd try checking who had insured the car over the last so many years, we have the "national insurance database" in the uk, i'm sure you have something similar, it may be hard to get information from them due to data protection, protection of privacy and so on.