The convertible Dodge Coronet was manufactured in 1967 and again in 1970. And it is extremely rare as only two cars were built in each model year. That means that there are only two 1967 and two 1970 Dodge Coronet convertibles. While the Dodge Coronet is not the prettiest convertible ever built, and there is nothing particularly innovative about the car, the fact that it is so rare has boosted its price the few times one of the four models in existence has made it to auction. For collectors, the fact that this car is so rare is enough to make them shell out big bucks for it.