A random parking-lot photo in Colorado caught a Dodge Challenger SRT Demon prototype months before its official reveal – a car that would go on to post the quickest quarter-mile and 0-to-60 time of any production vehicle ever built. Its 840-horsepower HEMI was so potent that NHRA banned it from sanctioned events without extra safety gear. Only 3,000 examples were ever built. Here’s what made this spy shot worth sharing.