It all started with a Ferrari. When San Diego real estate magnate Edward Kaen recently found himself craving one of the Italian sports cars it dawned on him that the same aesthetics that make the Ferrari so irresistible could (and should) be applied to a hotel. Kaen promptly bought a land-marked, five-story brick building in the city’s trendy Gaslamp District (it is to San Diego what Soho is to New York City). 

He hired Pininfarina Extra, a spin off of the design team responsible for the Ferrari and the Maserati, to conjure up everything from the colors (red and black), to the materials (steel, dark woods, polished concrete) to the furnishings (voluptuous chairs, closets that pull out vertically and see-through tinted plastic showers—its cooler than it sounds).

The unique result...