The R/T exhaust is pretty decent as it is. A full catback will change the sound.

 

I have had a r/t on my sxt and it didnt sound ricey in my op not like the srt or my borla which those sound really loud and in need of a glasspack so I think it would be worthless in my op to get a glasspack for your r/t exhaust. Unless you have an aftermarket exhaust that they put on if you didnt buy it new thats the only way it would sound ricey as you say.Your stock exhaust should be quiet and not ricey at all if its a stock r/t exhaust like you think.