Nissan may add a drop-top variant of the Altima in the years to come. If the project is given the go-ahead, the drop-top will be based on the Altima Coupe. The Altima Coupe is based on the Altima Sedan, but only shares an interior and hood. The low-priced convertible segment isn't what we call "successful" these days as sales are slow, mainly because of the lack of new models in the segment.
Main rivals of the Altima Convertible would include the Toyota Solara Convertible, Chrysler Sebring Convertible and the Pontiac G6 Convertible.
[Source: Motor Authority]