Road & Track tested premium leather cleaners on a well-worn Jaguar XJS to determine whether modern products can restore decades-old hide or simply disappoint. The publication subjected several cleaners to rigorous testing on the British sports car's interior. Restoring aged leather demands products that penetrate grime without degrading the material itself. A cleaner must balance aggressive cleaning action with gentle handling of delicate, aged surfaces. The XJS served as the perfect test bed. Its interior has weathered decades of use, presenting genuine challenges that showcase each product's real-world performance rather than marketing promises. Road & Track identified which cleaners actually revive worn leather and which ones crack under pressure, literally. Enthusiasts restoring classic cars need products that work on authentic problem leather, not pristine showroom examples. The publication's findings cut through manufacturer claims. Specific products emerged as standouts for serious restoration work. Others fell short when confronted with genuine wear patterns and sun damage. For owners of classics like the XJS, selecting the right cleaner separates successful interior restoration from costly mistakes. Road & Track's testing provides the data-driven guidance collectors need before investing in leather care products.