The economics of the custom business in Japan are very different to what we usually see in the west. Most of the top builders have a loose formula that they’ve constantly refined over the years, using a small number of high-quality parts suppliers. It means they’re not reinventing the wheel with every build; they know what works and what doesn’t. AC Sanctuary is one of the best-known examples of this approach. The company has built dozens of Kawasaki café racers—“resto-mods,” if you like—and now has several stores scattered around the country. It’s verging on small-scale production, like a boutique supercar