Did you get a check engine light too? I've had a start/stop warning along with check engine light come on and go off a few times. Had the dealer plug into the car last time it popped up and it was a an emissions evap leak warning which disables start/stop and locks the car in N mode. Not a big deal at all, just chock it up to Italian quirks I guess. Could be a small vacuum leak in the emissions system but we checked all the hoses and connections and everything looked fine. Like I said I've had it pop up a handful of times over the past year of ownership and it always goes away after a drive cycle or two. Nothing to worry about though.