Saint-Tropez for lunch, the Corniches by vintage Carrera and the biggest DJ event Cannes has ever hosted. During the Cannes Film Festival , the coastline transforms into a playground of superyachts, Champagne-fueled beach clubs, high-traffic helicopter routes and pop-up velvet-rope parties.  Here are THR ‘s tips for some things to do beyond the usual Croisette spots. By Land: Cruise the Corniches  Nothing captures the romance of the Côte d’Azur quite like driving the famed three Corniches — the trio of winding coastal roads connecting Nice to Menton high above the Mediterranean — in a vintage convertible (classicdrivers.co). With the top down and sea air rushing past, the route that passes through towns such as Èze, Saint-Jean-Cap-Ferrat and Beaulieu-sur-Mer feels lifted from an old Hollywood film.…