Also spelled as "Sil-80," it is a popular modification for the Nissan 180SX that refits it with the front end of a Nissan Silvia, therefore having the front of a Silvia and the rear of a 180SX. The inverse (S13 with 180SX front end) exists as the less-popular Nissan Onevia.
500 officially licensed Sileighties were built by Japanese tuning company Kid's Heart. Unofficial Sileighties were usually created to repair damaged 180SX models since new Silvia front-ends were cheaper than the 180SX's, likely due to their lack of pop-up headlights.
The Sileighty is most notable for it's appearance in Initial D, where it is driven by Satou Mako and her navigator Sayuki.