You do what you like.
I'll arrive at work at 11 for my first meeting, having gotten a solid 1.5 hours of uninterrupted work done already, and be wrapping up any collaboration in order to return to my mobile cubicle by 4.
Of course, I'll still be available via skype. The morning stand up may happen while everyone is leaving their driveway.
Soon enough this new daily routine is going to be about as disruptive to productivity in the office as taking lunch, since almost everyone with a car will taking advantage of it. The start and ends of business days are going to become 'private', with people keeping their heads down, and interacting via video and chat/mail as the norm, with face-to-face work performed during the middle of the day.
We may even have to do away with lunchtimes as we know them, since they take away from prime face-to-face work time. Or perhaps, with all the other communication going on, daily team-bonding time over food might be one of few on going reasons for direct interactions.
And vehicles are going to start being designed to be really comfortable to work/play in. Every mid-morning, people are going to have to choose between getting up from the work they are stuck into and moving to the desk in their office, or staying focused on the task at hand. Eventually, people are going to start choosing the privacy and comfort of their car over the relative space of a cubicle, and more and more people are going to start working from the parking lot. Companies may even start expecting a portion of their workforce to bring their own vehicles, in the manner of 'bring your own device' and alter/reduce their use of offices.
Of course, things could go the other way: in the city, you'll want to the car to go pick up the groceries and do errands, and then find a in a nice empty shaded spot out of town for the day, and to find a new spot if anyone sketchy shows up.
This is just one tiny, tiny change as we move from a civilizations of vehicles to a civilization of intelligent transport. Cars and buses are about to be replaced by the equivalent of very small mobile homes/buildings.