Thats obvious if theres an ebay seller in the car

Forget that, the insurance company leeches are going to take a big hit to their pockets.

Well what a good question.

I suspect it will go as follows;

If it's a large driverless Mercedes it will have diplomatic immunity.
If a BMW it will be charged to the dealership.
If it's a mini cab then the cost of tracking down the legal owner will far exceed the fine.
If you are a worker on minimum wage it won't affect you because you can't afford one, however you will be done for overtaking a driverless car at 25mph in a 20 mph area, you will also be done for driving without due care, for having two tyres which are deemed to be below the tread limit, be breathalised and fail due to not having sobered up from the night before and finally just for having the audacity to drive a motorised vehicle.

There's only one thing more pointless than trying to argue with the state and that's trying to argue with a machine. A human would plead not guilty by reason of insanity.  A machine would plead not guilty by reason of impunity.