Hennessey-tuned Cadillac hits 220 mph on Texas highway

Texas tuner John Hennessey's work on big Detroit iron has its acolytes and detractors, but the man knows how to show off his wares. To highlight the top-speed performance of some of his big rigs, Texas authorities let him take a full-speed blast down the state's newest toll road outside Austin that opened today, one that features an 85-mph speed limit. It's just long enough for the 1,200-hp, twin-turbo Cadillac CTS-V coupe to hit 220.5 mph.