I know something about this! I bought a fairly new (but used) truck and the (*#$ car lot didn't file any paperwork. According to Texas law, and it sounds a lot like MN law, for me to get straight, I have to:
- Get a "letter of rejection" from the state ($2)
- Take the letter of rejection to my county tax office. They will either grant me a tax hearing to relieve me of having to pay taxes again, or require me to get a bond. Naturally, they required me to get a bond. Why? As insurance for the truck against repossession for 3 years. In other words, it is entirely possible that someone out there has a title to the truck and tries to take possession. The bond requires the bonding company (a.k.a. insurance company) to pony up for the value of the vehicle. This keeps it out of state courts should there be a disagreement.
- Go to the bonding company who will write you a bond using either an appraisal or the value that the state put on the vehicle in their letter of rejection. My purchase was for $4K, the value was set at $8K, and the bond cost $120.
- Take the bond with your fat wallet, and go BACK to the tax office and pay for title, tax, and license AGAIN. This gets you legal with the state.

Then I get to file a claim in small claims court to recoup my previously paid TTL + the bond cost.

I don't think anyone can step forward after three years: you've paid for the bond, you've duly paid taxes on the vehicle like a good citizen for three years, and the other person has not.

When it comes down to it, what else can you do? This is the legal process as defined by my state. I think I'd win any dispute so long as I keep my file of papers.

By the way, when you get that letter of rejection, the state sends a letter to the title holder telling them that someone is trying to make claim to the vehicle. This is their official notice of a problem. I called the previous owner and gave them an advance warning of what was happening. They were thankful about me letting them know, and I have no concerns about any future attempt at trying to take possession after 3 years.

Bill