Longer trips surely equals fly and hire, or train and hire depending on country. Or even train and taxi if destination is metropolitan.assuming level 5 turns up. They’ll be expensive. And if they’re that good why not club together with your street to buy one and share it as you don’t have to leave it where you drive it. Or they’ll just end up the equivalent of taxis, only without drivers.
So functionally for many of us, we already have level 5 AI - its called a taxi. They won’t be cheaper because although they’ll get rid of drivers, the cars are more expensive and anyway rates will likely be regulated.
I guess the only gap is for longer trips, which you can rent for. Woudl be curious to see a cost breakdown for replacing eg a second car with walking/cycling/taxi/rentals for short/medium/long trips, vs the cost of owning a car, paying for parking etc.