HUSKY LINERS work! My buddy has a 2013 R/T w/Beats and it fits. On the Husky Trunk Liner, there is a line that you cut the section of the trunk mat out that still leaves a lip for those with the Beats system. Fits great and looks great! I have the same liner in my 2014 SRT without Beats and fits great in there too.
http://www.autoanything.com/cargo-liners/64A5194A0A0.aspx
Stock picture but this is the one I ordered. Good luck!
http://www.autoanything.com/cargo-liners/64A5194A0A0.aspx
Stock picture but this is the one I ordered. Good luck!