I doubt there will be much profit at $35,000, at least not for a while. But does there need to be? As long as it's profitable on average, the base model can just break even. I bet a lot of buyers will pay for the Autopilot option, for example, and that's pure profit.
The 3 is going to be a real test here. Not that they can make the car but that those expecting to get one at 35k actually get one and on a timely basis. Then throw in, is there any profit at that price point when factoring in all related costs?