Question: A Sileighty is a Nissan 180SX with headlights, front fenders, hood and front bumpers installed from a long-running line of sport coupes based on what?
Related documents: [0]  [DOC] The Nissan Silvia is the name given to the company's long-running line of sport coupes based on the Nissan S platform. Although recent models have shared this chassis with other vehicles produced by Nissan (most notably the European 200SX and North American 240SX in the S13 and S14 generations, and 180SX in the Japanese market), the name "Silvia" is not interchangeable with the chassis codes. The Nissan Silvia's main competitors worldwide were the Honda Prelude, Mazda MX-6, Toyota Celica, Mitsubishi Eclipse, and Honda Integra. [END] 
[1]  [DOC] A Sileighty (シルエイティ ) is a Nissan 180SX with a Nissan Silvia's headlights, front fenders, hood, and front bumper installed, hence the 'Sil' in front and the 'eighty' rear. [END] 
Answer: 
Nissan S platform
Nissan S platform