I think this is really silly. How is living uncomfortably in a car make you relentlessly resourceful? It seems entirely counter productive. You won't get good rest and even have a decent work environment. Half the fun of creating a start-up is not having to go to an office every day in peak hour traffic.
Right now I'm sitting outside in my backyard working away. It's a beautiful quite day and I have already achieved heaps. If you already have a nice apartment then you're better off working from there.