Yes, as RzeroB said, the V5X code is for body side moldings with the black insert. Different years had different options of the colors available as an option.
I think I agree with duodec. Not exactly sure as I haven't looked at mine and I assume the Challengers and the Barracudas were the same but I think there were like little studs that the molding attached to. The little studs (sorry if that's the wrong term) stuck out from the fenders/body and the molding has plastic clips that they attach to. If memory serves me right I think I saw a resto picture and the owner chose not to put the molding back on and you can see the areas where he ground down the studs along the side of the body.
A lot of people got rid of them as it messes up any stripe you might want to put on. In most cases if you got the body side molding I think the stripe if there was one was deleted. I think that's the way it worked. You might see a car with molding and a stripe today but I'm not sure that's the way they came from the factory, but who knows...
This may not only pertain to stripes. My car is a '72 Rallye and the Rallye cars are supposed to have the side louvers on the front fenders but my car did not come with them presumably due to the molding. The original owner verified that the front fenders are original and there are no holes in the front fenders.
dusty, you had holes for yours?
I'll have to look closer at my car when I go out. I agree as you have said, they are very hard to find, especially in good shape not all mangled.