The general recommendation is to arrive at the airport car park at least 2 hours before a domestic flight and 3 hours before your international flight departure time. Three hours should give you enough time to park your car, get a shuttle to the airport terminal, check-in for your flight, go through security screening, and make your way to your departure gate. Overall, it's better to arrive earlier than later to ensure you have plenty of time to navigate the airport and avoid any unnecessary stress or rushing.