In San Diego you can really appreciate driving with the top down." So says Ralph Rubio, explaining his fondness for the 1977 Porsche 911S Targa pictured at right. He bought the car in 1986; is its third owner. A Lexus and Jeep Cherokee fill out the family garage. Appropriately, Rubio's president's same fair-weather driving philosophy can apply to Phoenix in the winter. That's where $16.5 million Rubio's Restaurants Inc. is headed early next year for its first expansion outside of Southern California. It’s a marketing natural: Zonies who flood San Diego in summer have purchased their share of the more than 20 million fish tacos Rubio's has sold. But first things first. The 30-location restaurant chain opens two restaurants this month, one in Carlsbad and the other (its third L.A. store) in Marina Del Rey.