Barrett-Jackson’s 2017 Northeast auction at Mohegan Sun led with a 1971 Dodge Hemi Challenger R/T and a pair of 1970 Plymouth ‘Cudas, and the production figures behind those cars explain the interest better than any catalog description. Chrysler built just 71 Hemi Challenger R/T hardtops for 1971, and fewer than 800 Hemi ‘Cudas across the model’s entire life. Read on for what those numbers mean and why documentation now decides the price.