Trump broke golf etiquette when he drove a cart across the greens at the Bedminister golf club in New Jersey. In fairness to the President, he owned the club, though others have noted that it is a regular habit. Even when meeting with other foreign leaders, he preferred taking a golf cart alone rather than walking with the others.

Despite regularly disparaging his predecessor for it, Trump golfed more often and more frequently at courses outside DC, costing taxpayers over $100 million by his third year in office.

The Washington Post – President Trump angers golf fans by driving golf cart on green. He apparently does this a lot.
Golf.com – WATCH: President Trump drives cart all over Bedminster green