I have spent much of 2026 scrolling through classifieds for performance cars that still make sense, and the 2004 Jaguar XJR keeps pulling me back. On paper, it sounds like a fantasy: a supercharged V8 luxury sedan, an aluminum body, rear-wheel drive, and a 0–60 mph time that can embarrass a modern Mustang or Toyota Supra, all for the price of a used economy car. In the real world, though,...