Quadratec Jeep YLJ Mixes Original And Modern Wrangler Cues In Rugged Way ++ The looks from the '80s with the technology from today. Quadratec is the largest independent retailer of aftermarket Jeep parts, and the company celebrates 30 years in business by building a unique Wrangler that mixes the first-gen (known internally as the YJ) and current JL model. Naturally, the business refers to this machine as the YJL. Starting with a JL Wrangler, Quadratec overhauls the front so that it has rectangular headlights, like on the YJ. These are not simple sealed-beam lamps like on an old Wrangler, though, because the company installs modern LEDs. The front bumper is simply a metal beam with circular auxiliary lamps on top.