In the United States and Canada, the car was sold simply as the "Datsun 610". The four-door sedans, a two-door hardtop coupé, and a five-door station wagon were available, and were marketed as a more luxurious and larger product than the 510. For 1973 and 1974, North America was the only market outside Japan to have its 610 HT models equipped with the unique, six-bulb tail lights that covered the entire rear panel, requiring the license plate to be mounted below the rear bumper. The car originally received criticisms for elevated noise levels and engine drivability problems; Nissan responded with engine improvements during 1973 and a new engine for 1974, mounted on new engine mounts to lower noise and vibration. The window seals were also modified, to lower wind noise.