GT3 refers to a category of racing cars that are designed for competition in various sports car racing series. These vehicles are based on production models but are modified for performance, safety, and aerodynamics. The GT3 class is popular in events like the FIA GT World Cup and the 24 Hours of Spa, allowing manufacturers to showcase their engineering capabilities. The regulations for GT3 cars are standardized, meaning that teams can compete with different brands while adhering to similar performance specifications. This creates a level playing field, encouraging close racing and strategic competition among teams representing brands like Porsche, Ferrari, and Audi.