LEXUS is having another lunge at the luxury SUV segment it helped define more than a decade ago, with the latest, third-generation RX. And what an improvement it is over the flaccid old one, bringing worthwhile strides in driveability, safety and refinement, while losing none of the cushiness or value that helped make the previous model a big success. Tested in top-line Sport Luxury guise, the RX350 won’t light a wick beneath keen drivers, but for everybody else there is plenty to savour.