Dado un texto de referencia sobre el Lotus Mark IX, ¿quién diseñó el coche?
El Lotus Mark IX (1955) fue un coche de carreras deportivo con carrocería de aluminio fabricado por Lotus Engineering Ltd. (LIE). Se fabricaron unos treinta coches deportivos de carreras Mark IX. Estaba estrechamente relacionado con el modelo Lotus Mark VIII (1954), del que sólo se fabricaron unos siete coches. Estos coches se basaban en gran medida en el innovador bastidor espacial del Lotus Mark VI (1952). Las carrocerías, muy aerodinámicas, fueron diseñadas por Frank Costin y construidas por Williams & Pritchard Limited.

Durante esta primera época, de 1954-1955, Lotus Engineering era todavía una empresa incipiente, y los coches se entregaban en diferentes estados de terminación por pedidos especiales. Al igual que el Mark VIII, el Mark IX estaba disponible en varias configuraciones y se montaban diferentes motores, como el MG de 1500 cc, el Connaught de 1500 cc y el Bristol de 2 litros. Sin embargo, la denominación Mark IX suele llevar el motor Coventry Climax de 1100 cc. Al parecer, se ofrecieron dos modelos de Mark IX: el "Club" y el "Le Mans", este último con frenos de tambor más grandes.
El Lotus Mark IX fue diseñado por Frank Costin.
Given a reference text about Lotus Mark IX, who designed the car?
The Lotus Mark IX (1955) was an aluminium-bodied sports racing car manufactured by Lotus Engineering Ltd. About thirty of the Mark IX sports racing cars were made. It was closely related to the Lotus model Mark VIII (1954), of which only about seven cars were made. These cars were largely based on the innovative space frame of the Lotus Mark VI (1952). The highly aerodynamic bodies were designed by Frank Costin and constructed by Williams & Pritchard Limited.

During this early era, of 1954–1955, Lotus Engineering was still a fledgling company, and cars were delivered in different states of completion on special orders. Similar to the Mark VIII, the Mark IX was available in various configurations and different engines, including the 1500 cc MG, 1500 cc Connaught and 2-litre Bristol were fitted. However, the Mark IX designation is most often powered by the 1100 cc Coventry Climax engine. Apparently, two models of Mark IX were offered – the "Club" and the "Le Mans", the latter of which had larger drum brakes fitted.
The Lotus Mark IX was designed by Frank Costin.