Ideally you wouldn't need to do the cup trick forever, once your child understands the importance of wearing their seatbelt.
U nga languteli leswaku swifafa swi ta hela hi siku rin'we, ngopfu-ngopfu loko n'wana wa wena a swi xiyile leswaku swifafa swakwe swi endla leswaku u n'wi nyika leswi a swi lavaka.