yes dodge did come with a convertable option on the ramcharger for only 3 yrs 75 76 77 or 76 77 78 i personally know the answer because i just got rid of a factory 1976 ramcharger convertable due to huricane katrina i live in new orleans and needless to say it drowned and was beyond restoring pics can be provided upon request [email protected]

Sources: my own personal work /play truck

Your freind most likely was driving a Chevrolet Blazer, the blazer is commen and it might be a plymoth trail duster or ram charger because they both had removable tops during specific years, try going to your librariey to look for a book called cars of the sensationle 70s, that should help you find the awnser to your question.

Perhaps it was a Plymouth Trail Duster. Plymouth had a Trail Duster that looks similar to the Ram Charger and offered an open body 4x4 Utility Model.