Your closest boutique is South Coast Plaza in Costa Mesa. Totally worth the drive up I-5 and I-405. Very near to Newport Beach (for reference). If you just need a scarf fix, Neiman Marcus in San Diego can do, but it won't be nearly as satisfying as visiting the Hermes store at SCP.
South Coast Plaza is AMAZING!! Beverly Hills indoors with free parking! Every important boutique is there - Hermes, Chopard, Vuitton, Cartier, Chanel,
Gucci, Van Cleef & Arpels, Tiffany, etc. Here is the link to their site:
South Coast Plaza