Models R30 to R34 of the Skyline are still popular cars for modifying by Japanese car enthusiasts from the 1980s to today. There are available features such as straight-6 engines, turbochargers, and the high-performance GT-R trim. While not distributed in the United States, the Skyline's prominence in video games, movies and magazines resulted in many such cars being imported there from 1999 to late 2005. Motorex petitioned the National Highway Traffic Safety Administration to allow 1990–1999 GT-Rs and GTSs to be imported, at the condition that they were changed to meet United States Federal Motor Vehicle Safety Standards.