Stand alone option. So what parts are put on a Challenger once someone by ordering a car and the M28 Option is generated. If it is a stand alone option then it will have nothing to do with other options such options as in the M moulding options. I have seen it on a few Challenger fender tags but that is just a letter and a number put together. What I am asking it what are the exact parts or pieces that this code is referring to that are put on a Challenger.