 Complete the following phrase:  In order to compete in the FIA GT World Cup in Macau, drivers had to compete in a Fédération Internationale de lAutomobile FIA-regulated championship based on GT3 regulations. On 11 September 2015, Audi, Aston Martin, Mercedes-Benz, McLaren and Porsche were announced as the five manufacturers that had been accepted to partake in the event and was open to any model of car meeting GT3 rules. Manufacturers were permitted to enter up to three drivers through privateer teams, and the teams that represented the manufacturers were allowed to field both gold and platinum ranked drivers; bronze and silver rated entrants were eligible on a case by case basis at the discretion of the FIA GT World Cup Committee. The entry list for the FIA GT World Cup was released on 7 October 2015. A total of 22 drivers were featured in the initial list of entries which included 2014 Macau GT Cup race winner Maro Engel, two-time Macau Grand Prix victor Edoardo Mortara and the 