Sovereign citizen was robbed of his unregistered car he was operating without a license, is distressed.

Why would they be driving on a road fully regulated by a separate country without some sort of agreement?

Because they somehow, deep down, subconsciously acknowledge that they're the liability in the situation, and any sort of contract just serves to hold them accountable.
Well, see, there's this multi-million dollar trust that gets registered in their NAME at birth by the gubmint, so now everything is free.
- But why would the gubmint register a trust with a sovereign country without a sort of agreement?

Assvice thus far:

null and void EXPECTO PATRONUM
- If at first you fail, try again AD ABSURDUM
- If he had just done "Accio Car" he could have avoided the trouble .
Void AB INITIO

They really do use contract law concepts like they are magic incantations.
- its just larping for chuds
Towing companies are famously assholes who will just straight up steal your car to the extent that the head of their professional org where I live was like, "yeah you really need to just tear the industry down and start from scratch."

All that to say, I'd love to see the reaction of the person at the yard to this nonsense.
- Police impounded the car because it wasn't registered and the driver didn't have a license. Normally I would agree with you, but the police and the towing company did the right thing here.
- A tow truck driver stole my friend’s car after he wrecked it.

Simple, prove that you never touched a publicly owned road. Otherwise, fuck off.

Well ackshually, due to the nuclear force, my atoms and my cars atoms never touch the road, we merely ride the electromagnetic repulsion

Edit: also I don't have an international treaty with the roads atoms
- Yea that’s the secret sauce right there. Did you enter into a contract with any atoms?
  
  No? Well then technically the state of California belongs to you and you never ever have to pay any bills, you know cause according to maritime law atoms can freely “travel”…
- By that definition nothing has ever touched anything on earth for billions of years outside of rare and expensive nuclear testing apparatus, therefor touching loses all meaning outside of the context in which it describes atoms interacting with each other's electromagnetic field as a result of kinetic energy transferal.
  
  Step out of the vehicle and place your hands on the hood.

There needs to be some kind of clinic to take people with this much delusion to.

I can actually understand this one to an extent. A driver's license and vehicle registration are only required to drive on public roads, not legal requirements for having a car. That said, taking a car onto a public road without the aforementioned is illegal and should result in a fine.

Driving an unregistered vehicle without any license on a public road is endangering others. So a fine would not be sufficient.

It's the same arguing as carrying an unregistered weapon without a license in public space. That would be confiscated as well instead of being fined.
- FWIW not everywhere has a requirement to register firearms.

Have them sell the car at auction and give the sovereign the cash.

They will not release a vehicle to break the law immediately. (How are you going to drive your unlicensed, unregistered vehicle home from the impound?)

It may be permissible to have the vehicle scrapped directly from.yhe impound.

Tow truck to bring car back to private property. (just can't drive it)