According to this CR blog article: Electronic stability control—more models going standard So the mandate goes into effect for 2012. And now Tesla has extended Roadster sales into 2012. So therefore it's being forced to add ESC, I suppose. I wonder if it was working on it anyway. When I spoke personally to Elon at the Model S unveiling in DC Jan 2009, his response to me about ESC was to the effect of, "No, why would the Roadster need ESC? It's not going to flip over." If they do add ESC, I hope it's a retroactive upgrade possibility. Probably a tall hope, though.