SAN FRANCISCO –Fun is what the RDX is all about, with sleek lines and an aggressive snout that tells people you mean business about a good time. It’s the new luxury, the new thing people will soon be focusing on as a full time pursuit. After eight long years spent thinking about families, terror, wars, and religion, it’s time to have some fun, darn it, so climb on in and crack open this turbocharger. It’s better than a six-pack in the parking lot of a NASCAR race, and goes almost as fast, too.