Of course there was an actual car for perhaps even all the stunts, I'm mostly just meaning that it was shot one block at a time, doing several takes on each stunt and some street scenes being a edited composite of across several takes. I saw them doing a couple practices for the one on California street (between the fake trolleys).
I get that you'll scoff at that being an a valid accusation of fakeness so don't waste your time. I was mainly responding to the facebook frenzy over it and folks marvelling at how "empty" SF was.