fooled by title

I should talk a lot of thing to you.
I purchased my car at 1999 in Eugene, Oregon and I move to SanFrancisco CA at 1999 by school transfering.
When I bought my car I paid in full in a week. I dont have receipt with me right now, but my old bank statement can shows me how much I paid by check to my dealer. and I moved to SanFrancisco CA and registered my vehicle withoout title. So I have California lisense plate but still under control of Oregon DMV for title.

I didnt get my Title. I registered my car without title and that was my time when I understand about title.
Im a foreinger and I really didnt know about What I have to do with my vehicle because that was too much different system. Now, I merely understand and I need title to sell my car until May 2004.because Im going back to my country at early in the Jun 04.

Now, I need my title, but when I contact with DMV Oregon several days ago, I heard I had finacial company and I need to get release letter in order to issue title. So, I contact financial company what DMV Oregon told me and it was WFS FINANCIAL.However, they said, they dont have any records about me. so I cannot get release letter. I checked title search internet, and I found one Lien/Loan reporting was happened at April.99. However, this did not show to me that what kind of situation Im in. I can sure I paid in full before this report added to your files.Also I even didnt get any payment coopons from that company before I move to SanFrancisco, CA. (about 4 month from purchasing date)

Now, Im totally out of idea what I have to do.
It was like 5 years ago since I purchased my car. And I have to sell my car. If not, I have to trash on the road and that gonna make me criminal in US. I contacted with Car dealer but owner of car dealer had been changed so they were unalbe to find my record. also, WFS financial told me they dont have Any records in there data base. And, Oregon DMV says I need release letter but how possibly can I get from where? My friends said Oregon DMV should have something to do for me such as issue title without release note.

I put all my information I have with me and if you required I can send you my old bank statement via fax that shows I wrote my rest of payment checks to my dealer.

This is really important, so please reply me asap.
Also, please give me information what is going to happen if I left country without selling or trading but trashing car. I should came back to United States 3 years later from now. And if I have criminal records INS won't let me in then I have to pay a lot of penalty to company where I am planing to work. So I have to do something for this un-exprected and the result of foolish event.