The most popular of the items that he sells? Bumper stickers that say, in all-caps, “I Bought This Before We Knew Elon Was Crazy.” For his vacation, Mr. Hiller asked a friend to cover for him.

"Thanks to its lightweight, nimble handling and exceptional value, the NT1100 Police promises to be a popular choice among U.S. motorcycle units." Consumers expressed understandable frustration at ...