Japanese consumers are raiding discount stores for everything from cheap shampoo to furniture. When it comes to automobiles, it's the Rolls-Royces and BMWs that are moving off the dealer lots.

Luxury imported cars costing ¥10 million ($96,500) or more surged 19 percent in the first nine months to 13,605 units, reaching the highest proportion of imports in a decade. At the other end of the spectrum, deliveries of minicars such as the Nissan Dayz, which starts at about $11,000, have slumped 11 percent to 1.3 million units.

Premium carmakers including BMW AG and Rolls-Royce Motor Cars Ltd. are wagering the gains at the top end will continue by adding dealerships with flashy new showrooms.