Its state dependent on whether the state you are physically in has the resources to enforce foreign LLC registration (hint: none do, with California being a big maybe)
Its state dependent on whether enforcement has any real consequences, such as whether there is any retroactive punishment or not (example: New York State actually gives retroactive protections for your foreign LLC even after you are sued in court and form a domestic LLC as required to have a better case, so the only consequence there is having to register once you get sued which costs a little money, no consequence for the property and this doesn't address a bill of sale for a car)
So, what happens when you get pulled over? Shrug, have all the papers? Point is that you can transfer any property this way by transferring the business that owns it with nobody knowing what the business actually owns.