“Our customers get a completely different perspective of Paris than they would by sitting on a bus,” says Remi Di Nino, co-founder of the Retro Tour company. “They discover the heritage and secrets of Paris down its lesser-known streets.” Three dapper operators—friends who go by the nicknames The Stylist, The Diplomat and The Magician—zip you from Concorde Square to the Arc de Triomphe and from the Eiffel Tower to the Champs-Élysées in classic motorcycle sidecars. Tours start at $100—with local insights tossed in for free.