The letters GLS appear on Hyundai cars, and they refer to the trim level of the specific car. Trim levels are packages that range from the basic factory model to the sport and limited-edition models. The 2014 Hyundai Elantra four door sedan, for example, has three trim levels.
The GLS Hyundai is not an official acronym, although various car retailers employ names such as the grand luxury sport and grand limited edition. The base trim level is the Hyundai Elantra SE. It comes standard with air conditioning and cruise control. Next is the Limited and GLS Sport, which include upgrades such as a stronger engine and sportier suspension.