There were 2 generations of the 240SX. The first lasted from
1989 to 1994, with the second lasting from 1995 to 1998. They were the S13 and S14 in Nissan's internal nomenclature.
These cars were sold in two body types: the coupe, which was sold in base, SE, and XE trims; and the hatchback, which was sold in base and SE trims. There is not a fastback version of the 240SX, even though Nissan often referred to the hatchback using that term. The design of the rear window and hinge location do not fit the technical definition of a hatchback.
These cars were powered by an I4 engine. First generation models got a single overhead cam, with later models getting a DOHC.
A convertible was added to the lineup in 1992. The 1994 model was essentially an afterthought stuck between the 1st and 2nd generation 240SX. It was still a 1st generation model, but it was only sold as a Special Edition convertible.
Although some models were considered underpowered, the 240SX is generally regarded as a great driving car, with some of the best handling on a car that doesn't cost more than $50,000.
These cars are popular on the used car market. There are many fans of the 240SX who devote a lot of time and money restoring them and making some modifications to the 240SX's various parts. The best place to buy a used 240SX is still eBay, which is the world's biggest car auction running 24/7. There are also pleny of parts on there.