Metro-North’s New Haven line passengers are getting a sleeker ride.

The first of 380 shiny M-8 cars rolled into Grand Central Terminal on a run from Stamford yesterday.

Metro-North promises they’ll be less breakdown-prone than older M-2, M-4 and M-6 cars, which had trouble in winter weather.

Twenty-six M-8 cars will be in service by spring, 80 by the end of the year, and all 380 will be running by late 2013.