The National Highway Traffic Safety Administration has officially deemed the Spyker C8 coupe and convertible roadworthy, thus completing a two-year certification process and making the Dutch exotics ready for sale in the U.S. The cars had already received approval from the E.P.A. a few months ago. Spyker plans to increase its network of U.S. dealers from 13 to 20 by the end of 2005, including the opening of a Las Vegas showroom in July. This means that what happens in Vegas can now be driven home.