This has puzzled me for a while... Pretty much any classic Dodge car you can think of has a Plymouth counterpart, and vice versa. Roadrunner <=> Superbee, GTX <==> R/T, 'Cuda <==> Challenger R/T, etc. The glaring exception seems to be the Charger. Why no Plymouth B-body fastback to complement it? Seems like the Plymouth guys would have wanted to cash in on the success of the Dodge.