Tesla does the same for their autopilot feature. It’s something like a $10k add on to the price of the car, or you can use it for a month for something like $100 or so.
My brother gave it a try for a trip from the LA area to Las Vegas. Signed up for it a couple of weeks before the trip to have it to play with, then cancelled it just before the month was up.
Just another way to get some more revenue out of their customers.
—Peter