Not sure about other states bit in Washington:
If you live here and purchase a vehicle then you're required to transfer title within 30 days. (I got a warning from the State Patrol on this after I bought a bike in CA and thought it was a good idea to let the tabs run out before transferring title. I got a verbal warning for the speeding thing which is why I got pulled over in the first place.)
I forget what it's called but if you don't have a title then you can still register an untitled vehicle. If, after 3 years, nobody has claimed the VIN then you can get a real title.