Dealers have received notice RRT 15-017 to replace the rubber valve stems on the 2015 Challengers with metal ones. Apparently, this cost cutting action resulted in leaks and TPMS warnings. The process to replace them takes about 15 minutes per wheel. The techs deflate the tire and reach in to remove the rubber stem and replace it. There is no need to remove the tire from the wheel and re-balance it.