A coupe is a fixed-roof car with a sloping rear roofline and one or two rows of seats. However, there is some debate surrounding whether a coupe must have two doors for passenger egress or whether cars with four doors can also be considered coupes. This debate has arisen since the early 2000s, when four-door cars such as the Mazda RX-8 and Mercedes-Benz CLS-Class have been marketed as "four-door coupes" or "quad coupes", although the Rover P5 was a much earlier example, with a variant introduced in 1962 having a lower, sleeker roofline marketed as the Rover P5 Coupe.