The accident happened on the Romney, Hythe and Dymchurch railway, during one of the Kent tourist attraction's busiest days of the year.
But no one was hurt, and by the end of the day services had been restored.
A replica steam engine struck the car on an unguarded level crossing near Greatstone-on-Sea, Kent, at about 5.15pm on Sunday. The car spun and scraped the side of the train, which was carrying about 150 passengers.
The engine is a one-third sized narrow-gauge replica - weighing nine tons.
A railway spokesman said: 'The passengers all thought it was a great adventure. We brought another train to the other side of the crash site and transferred them, and by the end of the day we were only running 30 minutes behind timetable.'
The 14-mile line through Romney Marshes, set up in 1926, carries thousands of visitors each year.