I'm doing some research for an article on a 1971 Challenger R/T, but there is vagueness about an R/T convertible.

Every source I see says there were no "factory" rag tops in '71, but there are a slew of them for sale. Are these aftermarket upgrades?

Also, I read there was a non-R/T version with all the same performance options, but no R/T emblems or VINs. What's the deal and why all the weirdness?