I have instaled a EONON 646A after market head unit on my Mustang 2000 with the mach 460 system ,everything works perfect ,but I ahve a problem with the FM tuner reception ,when the car is stationnary it's ok ,but when the car is in the moove i lost the reception .Could it be a ground problem , the FM tuner with the stock head unit was perfect . The after market dvd player I have instaled have a antenna cable in his back. I have connected the antenna cable on the connector of this cable , I have noticed that the stock heaunit have the connector directly in the back of the head unit (directly in the unit) I supposed it make a better ground with the head unit.Does put a ground cable from the antenna ground to the body of the after market head unit will help resove the problem ,I need advice before starting this modification ,thanks in advance to you all.